Useful math tools

PROFESSIONALTOOLS - 得到专业武器NUTTERTOOLS - 得到神秘武器PRECIOUSPROTECTION - 装甲全满ASPIRINE - 体力全满YOUWONTTAKEMEALIVE - 通缉级别+2LEAVEMEALONE - 通缉级别变为0APLEASANTDAY - 好天气ABITDRIEG - 阴天CATSANDDOGS - 雨天CANTSEEATHING - 雾天PANZER - 得到一辆坦克LIFEISPASSINGMEBY - 时间流逝加速BIGBANG - 附近车辆爆炸STILLLIKEDRESSINGUP - 改变玩家外貌FIGHTFIGHTFIGHT - 街上的市民互相残杀NOBODYLIKESME - 攻击市民造成更大伤害OURGODGIVENRIGHTTOBEARARMS - 每个人都拥有武器ONSPEED - 行动速度加快BOOOOOORING - 行动速度减慢ICANTTAKEITANYMORE - 自杀GREENLIGHT - 全部交通信号变为绿灯MIAMITRAFFIC - 行人加速TRAVELINSTYLE - 飞车ROCKANDROLLCAR - 得到豪华轿车RUBBISHCAR - 得到垃圾车GETTHEREFAST - 得到大马力车MYSONISALAWYER - 变成律师ROCKANDROLLMAN - 变成摇滚歌手ONEARMEDBANDIT - 变成武装强盗IDONTHAVETHEMONEYSONNY - 变成黑手党成员GETTHEREQUICKLY - 得到快车GETTHEREVERYFASTINDEED - 得到拉力赛车GETTHEREAMAZINGLYFAST - 得到最快的跑车FANNYMAGNET - 吸引女性CHEATSHAVEBEENCRACKED - 变成秃顶CERTAINDEATH - 嘴里抽雪茄想要密码的来：STSTKSDUATDWDGHSGDJADGJSDYUAUDGUGD=超音速战斗机RENHUEIFEISASNXF=人能在天上走ZDFEIWGFSFDFMKILLJLIUIFJ=增加20个保镖ADGUDSGFGDFIEHZZZWHIDEDIUEDH=变出潜水艇BIANDUGSDUSDOIEIDWHYEIDHWEIYDIUEWYDUISHADHSAKLHD=变出飞碟ASDSYDWUSGEIWFIXN=警察永远不会打你SAJDHWIEFHYEHFIEDZX=变成美国总统谁也不能打你DSDUCNXMBCEYWONFTIWWDSDFOYEFEOI=变出火箭飞行器AGDYWGDASKXNEIYRUEU=变成超人可在天上飞SDGSSDFEFUYSXHNUIYFETUEYXHIERYWIEYRSD=变出20个军人帮你打SWYEUWYSKHDUFGDOASHDHOWIYDUIWEUIDAXMWIREOIKSXJNWIERYIEWYR=天上出现一座城市SJKASHEWEIUGFHIUFYDSXNNKWNDOJRFRGPRFJ=变出宇宙飞船比战斗机还快ERITYEJCENIERUT=能游泳潜水这些可是超级秘籍希望大家用起了不要到处传,用不起把我杀了!!ASDIXNSIDYEWDNIXWRE=热气球UYTEDEOURXMYFEOIWHFDEITUORTU=激光枪,一枪可把坦克打爆WSIEDJCMEITHEWUOEWUWEURTOEXCJSWOEIEJETUOWEFEWMD=超级猛男一拳可将坦克打飞XZCMHREKCVMKGRJ=变出自行车还可在天上飞ETUEJSMNCEURUREYG=穿墙EIWYRFWXDIFIERWEKDEOUWROETROET=车子无敌TUSKSJSFIEYFIY=星战激光剑希望大家不要外传~~ahhelovemonvy航空母舰hsadiusasnmdcxuzedr摩托下水LXGIWYL = 暴徒武器KJKSZPJ = 专业武器UZUMYMW = 疯狂武器HESOYAM = 生命、护甲满，加25万美圆OSRBLHH = 增加两星通缉度ASNAEB = 清除通缉程度AFZLLQLL= 万里无云ICIKPYH = 阳光明媚ALNSFMZO= 阴云密布AUIFRVQS= 阴雨绵绵CFVFGMJ = 大雾弥漫YSOHNUL = 时钟加快PPGWJHT = 操控加快LIYOAAY = 操控减慢AJLOJYQY=行人互相攻击，得到高尔夫球杆BAGOWPG = 得到一大笔奖励FOOOXFT = 行人全副武装AIWPRTON= 刷新一辆坦克KRIJEBR = 刷新一辆StretchUBHYZHQ = 刷新一辆TrashmasterRZHSUEW = 刷新一辆CaddyCPKTNWT = 所有车辆爆炸XICWMD = 隐行车辆PGGOMOY = 完美操控SZCMAWO = 自杀ZEIIVG = 交通信号灯变绿YLTEICZ = 司机有攻击性LLQPFBN = 车辆变粉色IOWDLAC = 车辆变黑色AFSNMSMW= 船只飞行BTCDBCB = 主角变胖JYSDSOD = 主角肌肉值最大KVGYZQK = 主角变得皮包骨ASBHGRB = 行人变成猫王BGLUAWML= 行人用武器攻击你，得到火箭发射器MROEMZH = 到处都是黑帮BIFBUZZ = 黑帮控制街道AFPHULTL= 忍者模式BEKKNQV = 吸引女性BGKGTJH = 交通工具慢速GUSNHDE = 交通工具快速RIPAZHA = 汽车飞行JHJOECW = 超级兔子跳JUMPJET = 刷新一辆HydraKGGGDKP = 刷新一辆Vortex Hovercraft JCNRUAD = 汽车一击必炸COXEFGU = 所有车辆得到一氧化二氮加速剂BSXSGGC = 车辆被撞击时会漂浮XJVSNAJ = 永远是午夜OFVIAC = 永远是晚上9点MGHXYRM = 雷暴天气CWJXUOC = 沙尘暴天气LFGMHAL = 超级跳跃BAGUVIX = 无限生命CVWKXAM = 无限氧气AIYPWZQP= 得到降落伞YECGAA = 得到火箭助行器AEZAKMI = 永远不会被通缉LJSPQK = 六星通缉（最高等级）IAVENJQ = 超级攻击AEDUWNV = 主角没有进食要求IOJUFZN = 暴动模式MUNASEF = 刺激模式WANRLTW = 无限弹药，不用换弹夹OUIQDMW = 驾驶时瞄准度全满THGLOJ = 减少路上的车辆FVTMNBZ = 交通工具变为乡村车辆SJMAHPE = 给任何人9mm突击步枪BMTPWHR = 乡村车辆，得到卡车装备OGXSDAG = 最大景仰值EHIBXQS = 最大性感度VQIMAHA = 驾驶技术全满OHDUDE = 得到一架HunterAKJJYGLC= 得到一辆QuadAMOMHRER= 得到一辆Tanker TruckEEGCYXT = 得到一辆DozerURKQSRK = 得到一架Stunt PlaneAGBDLCID= 得到一辆Monster侠盗飞车4,罪恶都市密码:THUGSTOOLS - 棍子类武器PROFESSIONALTOOLS - 枪类武器NUTTERTOOLS - 变态武器PRECIOUSPROTECTION - 加满防弹衣ASPIRINE - 加满血YOUWONTTAKEMEALIVE - 加2个警察抓你的星星LEAVEMEALONE - 警察星星变零APLEASANTDAY - 好天气ALOVELYDAY - 超好天气ABITDRIEG - 云天CATSANDDOGS - 雨天CANTSEEATHING - 小雨天PANZER - 给你个坦克LIFEISPASSINGMEBY - 时间过得更快BIGBANG - 附近所有车子爆炸STILLLIKEDRESSINGUP - 换玩家的人物FIGHTFIGHTFIGHT - 街上人打架NOBODYLIKESME - 街上人被你装了会跌到OURGODGIVENRIGHTTOBEARARMS - 街上所有人有武器ONSPEED - 走的更快BOOOOOORING - 走的更慢WHEELSAREALLINEED - 车子不见..只有轮子COMEFLYWITHME - 苍蝇飞来飞去GRIPISEVERYTHING - ???CHASESTAT - ???CHICKSWITHGUNS - ??? ICANTTAKEITANYMORE - 自杀GREENLIGHT - 所有红绿灯变绿MIAMITRAFFIC - 路上车子开的很快AHAIRDRESSERSCAR - ??? IWANTITPAINTEDBLACK - ???TRAVELINSTYLE - 车子会飞THELASTRIDE - 给你一辆葬礼车ROCKANDROLLCAR - 给你一辆limoRUBBISHCAR - 给你一辆垃圾车GETTHEREFAST - 给你一辆 SABRE TURBO BETTERTHANWALKING - 给你一辆caddy LOOKLIKELANCE - LANCE SKIN MYSONISALAWYER - LAWYER SKIN ILOOKLIKEHILARY - HILARY SKIN ROCKANDROLLMAN - ROCK AND ROLL MAN SKIN ONEARMEDBANDIT - ONE ARMED BANDIT SKIN IDONTHAVETHEMONEYSONNY - MAFIOSI SKIN SEAWAYS - ???LOADSOFLITTLETHINGS - ???HOPINGIRL - 没用AIRSHIP - ???FOXYLITTLETHING - MAFIOSI DAUGHTER SKIN WELOVEOURDICK - SCOTTISH SKIN GETTHEREQUICKLY - 车子超快GETTHEREVERYFASTINDEED - 车子超超快GETTHEREAMAZINGLYFAST - 车子超超超快FANNYMAGNET - 女人都会被你吸引CHEATSHAVEBEENCRACKED - BALDGUY SKIN CERTAINDEATH - 嘴里放跟烟DEEPFRIEDMARSBARS - 没用PROGRAMMER - 没用THUGSTOOLS - 棍子类武器PROFESSIONALTOOLS - 枪类武器NUTTERTOOLS - 变态武器PRECIOUSPROTECTION - 加满防弹衣ASPIRINE - 加满血YOUWONTTAKEMEALIVE - 加2个警察抓你的星星LEAVEMEALONE - 警察星星变零APLEASANTDAY - 好天气ALOVELYDAY - 超好天气ABITDRIEG - 云天CATSANDDOGS - 雨天CANTSEEATHING - 小雨天PANZER - 给你个坦克LIFEISPASSINGMEBY - 时间过得更快BIGBANG - 附近所有车子爆炸STILLLIKEDRESSINGUP - 换玩家的人物FIGHTFIGHTFIGHT - 街上人打架NOBODYLIKESME - 街上人被你装了会跌到OURGODGIVENRIGHTTOBEARARMS - 街上所有人有武器ONSPEED - 走的更快BOOOOOORING - 走的更慢WHEELSAREALLINEED - 车子不见..只有轮子COMEFLYWITHME - 苍蝇飞来飞去GRIPISEVERYTHING - ???CHASESTAT - ???CHICKSWITHGUNS - ??? ICANTTAKEITANYMORE - 自杀GREENLIGHT - 所有红绿灯变绿MIAMITRAFFIC - 路上车子开的很快AHAIRDRESSERSCAR - ??? IWANTITPAINTEDBLACK - ??? TRAVELINSTYLE - 车子会飞THELASTRIDE - 给你一辆葬礼车ROCKANDROLLCAR - 给你一辆limo RUBBISHCAR - 给你一辆垃圾车GETTHEREFAST - 给你一辆 SABRE TURBO BETTERTHANWALKING - 给你一辆caddy LOOKLIKELANCE - LANCE SKIN MYSONISALAWYER - LAWYER SKIN ILOOKLIKEHILARY - HILARY SKIN ROCKANDROLLMAN - ROCK AND ROLL MAN SKIN ONEARMEDBANDIT - ONE ARMED BANDIT SKIN IDONTHAVETHEMONEYSONNY - MAFIOSI SKIN SEAWAYS - ??? LOADSOFLITTLETHINGS - ???HOPINGIRL - 没用AIRSHIP - ???FOXYLITTLETHING - MAFIOSI DAUGHTER SKIN WELOVEOURDICK - SCOTTISH SKIN GETTHEREQUICKLY - 车子超快GETTHEREVERYFASTINDEED - 车子超超快GETTHEREAMAZINGLYFAST - 车子超超超快LXGIWYL = 暴徒武器KJKSZPJ = 专业武器UZUMYMW = 疯狂武器HESOYAM = 生命、护甲满，加25万美圆OSRBLHH = 增加两星通缉度ASNAEB = 清除通缉程度AFZLLQLL= 万里无云ICIKPYH = 阳光明媚ALNSFMZO= 阴云密布AUIFRVQS= 阴雨绵绵CFVFGMJ = 大雾弥漫YSOHNUL = 时钟加快PPGWJHT = 操控加快LIYOAAY = 操控减慢AJLOJYQY=行人互相攻击，得到高尔夫球杆BAGOWPG = 得到一大笔奖励FOOOXFT = 行人全副武装AIWPRTON= 刷新一辆坦克KRIJEBR = 刷新一辆StretchUBHYZHQ = 刷新一辆Trashmaster RZHSUEW = 刷新一辆CaddyCPKTNWT = 所有车辆爆炸XICWMD = 隐行车辆PGGOMOY = 完美操控SZCMAWO = 自杀ZEIIVG = 交通信号灯变绿YLTEICZ = 司机有攻击性LLQPFBN = 车辆变粉色IOWDLAC = 车辆变黑色AFSNMSMW= 船只飞行BTCDBCB = 主角变胖JYSDSOD = 主角肌肉值最大KVGYZQK = 主角变得皮包骨ASBHGRB = 行人变成猫王BGLUAWML= 行人用武器攻击你，得到火箭发射器MROEMZH = 到处都是黑帮BIFBUZZ = 黑帮控制街道AFPHULTL= 忍者模式BEKKNQV = 吸引女性BGKGTJH = 交通工具慢速GUSNHDE = 交通工具快速RIPAZHA = 汽车飞行JHJOECW = 超级兔子跳JUMPJET = 刷新一辆HydraKGGGDKP = 刷新一辆Vortex Hovercraft JCNRUAD = 汽车一击必炸COXEFGU = 所有车辆得到一氧化二氮加速剂BSXSGGC = 车辆被撞击时会漂浮XJVSNAJ = 永远是午夜OFVIAC = 永远是晚上9点MGHXYRM = 雷暴天气CWJXUOC = 沙尘暴天气LFGMHAL = 超级跳跃BAGUVIX = 无限生命CVWKXAM = 无限氧气AIYPWZQP= 得到降落伞YECGAA = 得到火箭助行器AEZAKMI = 永远不会被通缉LJSPQK = 六星通缉（最高等级）IAVENJQ = 超级攻击AEDUWNV = 主角没有进食要求IOJUFZN = 暴动模式MUNASEF = 刺激模式WANRLTW = 无限弹药，不用换弹夹OUIQDMW = 驾驶时瞄准度全满THGLOJ = 减少路上的车辆FVTMNBZ = 交通工具变为乡村车辆SJMAHPE = 给任何人9mm突击步枪BMTPWHR = 乡村车辆，得到卡车装备OGXSDAG = 最大景仰值EHIBXQS = 最大性感度VQIMAHA = 驾驶技术全满OHDUDE = 得到一架HunterAKJJYGLC= 得到一辆QuadAMOMHRER= 得到一辆Tanker TruckEEGCYXT = 得到一辆DozerURKQSRK = 得到一架Stunt PlaneAGBDLCID= 得到一辆Monster作者： 220.172.234.* 2005-7-12 16:45 回复此发言--------------------------------------------------------------------------------139 回复 138：我知道狭盗飞车所有秘籍LXGIWYL = 暴徒武器KJKSZPJ = 专业武器UZUMYMW = 疯狂武器HESOYAM = 生命、护甲满，加25万美圆OSRBLHH = 增加两星通缉度ASNAEB = 清除通缉程度AFZLLQLL= 万里无云ICIKPYH = 阳光明媚ALNSFMZO= 阴云密布AUIFRVQS= 阴雨绵绵CFVFGMJ = 大雾弥漫YSOHNUL = 时钟加快PPGWJHT = 操控加快LIYOAAY = 操控减慢AJLOJYQY=行人互相攻击，得到高尔夫球杆BAGOWPG = 得到一大笔奖励FOOOXFT = 行人全副武装AIWPRTON= 刷新一辆坦克KRIJEBR = 刷新一辆StretchUBHYZHQ = 刷新一辆Trashmaster RZHSUEW = 刷新一辆CaddyCPKTNWT = 所有车辆爆炸XICWMD = 隐行车辆PGGOMOY = 完美操控SZCMAWO = 自杀ZEIIVG = 交通信号灯变绿YLTEICZ = 司机有攻击性LLQPFBN = 车辆变粉色IOWDLAC = 车辆变黑色AFSNMSMW= 船只飞行BTCDBCB = 主角变胖JYSDSOD = 主角肌肉值最大KVGYZQK = 主角变得皮包骨ASBHGRB = 行人变成猫王BGLUAWML= 行人用武器攻击你，得到火箭发射器MROEMZH = 到处都是黑帮BIFBUZZ = 黑帮控制街道AFPHULTL= 忍者模式BEKKNQV = 吸引女性BGKGTJH = 交通工具慢速GUSNHDE = 交通工具快速RIPAZHA = 汽车飞行JHJOECW = 超级兔子跳JUMPJET = 刷新一辆HydraKGGGDKP = 刷新一辆Vortex Hovercraft JCNRUAD = 汽车一击必炸COXEFGU = 所有车辆得到一氧化二氮加速剂BSXSGGC = 车辆被撞击时会漂浮XJVSNAJ = 永远是午夜OFVIAC = 永远是晚上9点MGHXYRM = 雷暴天气CWJXUOC = 沙尘暴天气LFGMHAL = 超级跳跃BAGUVIX = 无限生命CVWKXAM = 无限氧气AIYPWZQP= 得到降落伞YECGAA = 得到火箭助行器AEZAKMI = 永远不会被通缉LJSPQK = 六星通缉（最高等级）IAVENJQ = 超级攻击AEDUWNV = 主角没有进食要求IOJUFZN = 暴动模式MUNASEF = 刺激模式WANRLTW = 无限弹药，不用换弹夹OUIQDMW = 驾驶时瞄准度全满THGLOJ = 减少路上的车辆FVTMNBZ = 交通工具变为乡村车辆SJMAHPE = 给任何人9mm突击步枪BMTPWHR = 乡村车辆，得到卡车装备OGXSDAG = 最大景仰值EHIBXQS = 最大性感度VQIMAHA = 驾驶技术全满OHDUDE = 得到一架Hunter AKJJYGLC= 得到一辆Quad AMOMHRER= 得到一辆Tanker Truck EEGCYXT = 得到一辆Dozer URKQSRK = 得到一架Stunt Plane AGBDLCID= 得到一辆Monster阅读(3761)|评论(0)。

math.evaluate用法全文共四篇示例，供读者参考第一篇示例：math.evaluate是一个用于执行数学表达式的JavaScript函数。

它可以帮助用户计算和解析包含数学表达式的字符串，并返回结果。

在处理动态生成的数学表达式时，math.evaluate可以提供很大的便利性。

在日常开发中，我们经常需要对一些数学表达式进行计算，比如计算一个动态生成的数学公式的结果。

这时，使用math.evaluate就可以方便地完成这一任务。

下面我们来看一下如何使用math.evaluate来进行计算。

我们需要引入math.js库。

math.js是一个强大的数学库，它提供了丰富的数学函数和工具，可以方便地进行数学运算和计算。

可以通过在项目中引入math.js库，来使用其中的math.evaluate函数。

在开始使用math.evaluate之前，我们需要确保已经引入了math.js库。

接下来，我们可以使用如下的代码示例来计算一个简单的数学表达式：```javascriptconst math = require('math.js');// 定义一个包含数学表达式的字符串const expression = "2 + 3 * 4";// 输出计算结果console.log(result); // 输出14```在上面的示例中，我们首先引入了math.js库，然后定义了一个包含数学表达式的字符串"2 + 3 * 4"。

接着使用math.evaluate函数对该表达式进行计算，最后输出计算结果14。

除了简单的加减乘除运算外，math.evaluate还支持更复杂的数学运算，比如三角函数、指数函数、对数函数等。

我们可以通过传入包含这些函数的数学表达式来计算它们的结果。

下面是一个包含三角函数的数学表达式的示例：// 定义变量的值const x = 3;// 使用math.evaluate计算数学表达式的结果const result = math.evaluate(expression, { x });第二篇示例：math.evaluate()是JavaScript中一个非常有用的函数，它可以将一个字符串作为数学表达式来计算。

英语作文关于数学公式的应用Mathematical formulas are used in many different fields for various applications. From physics to engineering, from finance to computer science, mathematical formulas play a crucial role in solving complex problems and making important decisions.In physics, mathematical formulas are used to describe the behavior of particles and waves, the motion of objects, and the interaction of forces. For example, the famous formula E=mc^2, proposed by Albert Einstein, describes the relationship between energy (E), mass (m), and the speed of light (c). This formula has had a profound impact on our understanding of the universe and has led to the development of nuclear energy and weapons.In engineering, mathematical formulas are used to design structures, analyze materials, and optimize processes. For instance, the formula F=ma, which describes therelationship between force (F), mass (m), and acceleration (a), is used to calculate the strength and stability of buildings, bridges, and machines. Engineers also use mathematical formulas to model fluid dynamics, heattransfer, and electrical circuits, enabling them to create innovative solutions for real-world problems.In finance, mathematical formulas are used to evaluate risk, estimate returns, and price financial instruments. For example, the Black-Scholes formula, developed by economists Fischer Black and Myron Scholes, is used to calculate the value of stock options and other derivatives. This formula has revolutionized the field of finance and has enabled investors to make more informed decisions about their investments.In computer science, mathematical formulas are used to develop algorithms, analyze data, and optimize performance. For instance, the formula for calculating the Fibonacci sequence is used in computer programs to generate a series of numbers that are widely used in various applications, such as in modeling population growth, predicting stock prices, and creating visually appealing designs.Overall, mathematical formulas are essential tools for solving problems, making predictions, and creating new technologies. They provide a universal language for expressing relationships and patterns, and they enable usto understand the world around us in a precise and systematic way.数学公式在许多不同领域中被用于各种应用。

除法用英语怎么说除法概念除法是四则运算之一。

已知两个因数的积与其中一个因数，求另一个因数的运算，叫做除法。

那么你想知道除法用英语怎么说吗?下面店铺为大家带来除法的英语说法，欢迎大家学习。

division英 [diˈviʒən]美 [dɪˈvɪʒən]除法单元 divider除法电路 division circuit除法时间 division time除法问题 division problem除法装置 division device乘法可用除法来验算。

Multiplication can be proved by division.用计算器或长除法来看一看。

Use a calculator or long division to see this.加法和除法都是计算方法。

Addition and division are forms of computation.你学会除法了吗?Have you learnt division?你的除法好吗?Are you any good at division?当我们想把物体分成相等的大小时，我们可以用除法。

We use division when we want to separate objects into groups of equal size.属性包含该除法运算的模数。

Property contains the modulus of the division.他儿子正在学习乘法和除法。

His son is learning to multiply and divide.什么时候我们用乘法和除法?When do we use multiplication and division?对于除法问题的答案叫做商数。

The answer to a division problem is the quotient.让学生概括和理解除法的意义。

Let the students generalize and understand the essence of division.属性包含除法运算结果的模数。

120第十章 附录10.1 Notebook 文件的存取用户在Mathematica 的Notebook 用户区使用完Mathematica 想退出Mathematica 系统或想调用以前的Notebook 文件，就涉及到Notebook 文件的存取操作。

保存一个Notebook 文件用户在Notebook 用户区使用完Mathematica 或因为有事要中途退出Mathematica 系统，退出时想保留调在Notebook 用用户区的内容以便下次调用，这种保存Notebook 文件的操作为：１）用鼠标点击Mathematica 系统集成界面右上角的关闭按钮，屏幕出现一个对话框,询问是否保存用户区的内容, 如图：图10.1 提示保存文件对话框２） 如果单击对话框的“否(N)”按钮, 则不保存Notebook 中的文件, 退出Mathematica 系统; 如果单击对话框的“取消”按钮，则返回Mathematica 系统集成界面；如果单击对话框的“是(Y)”按钮, 则在保存Notebook 文件窗口的左上部分的文件名窗口先提示你用一个具有扩展名为 .ma 的文件名来保存用户区内的内容, 如果你想以另一个文件名保存该文件,可以在文件名窗口键入你自己的文件名,并选择好驱动器(Drives)和子目录(Directories)然后单击OK 按钮,既可以达到保存Notebook 文件在相应驱动器的对应目录下的目的,同时退出Mathematica 系统。

Notebook 文件窗口如图：图10.2 保存Notebook文件窗口打开一个Notebook文件用户在Mathematica 的Notebook用户区如果要打开一个Notebook文件，对应的打开Notebook文件的操作为:1)在在Mathematica的工作窗口键入Ctrl+ O,调出如下Open窗口:图10.3 打开Notebook文件窗口2)在打开Notebook文件窗口中的文件名窗口键入想要打开的文件名,并选择好对应的驱动器(Drives)和子目录(Directories), 然后单击OK按钮,既可以把对应的Notebook文件调入Notebook工作区。

Unicode Nearly Plain-Text Encoding of MathematicsVersion 3Murray Sargent IIIPublisher Text Services, Microsoft Corporation10-Mar-101.Introduction (2)2.Encoding Simple Math Expressions (3)2.1Fractions (4)2.2Subscripts and Superscripts (6)2.3Use of the Blank (Space) Character (7)3.Encoding Other Math Expressions (8)3.1Delimiters (8)3.2Literal Operators (10)3.3Prescripts and Above/Below Scripts (11)3.4n-ary Operators (12)3.5Mathematical Functions (13)3.6Square Roots and Radicals (13)3.7Enclosures (14)3.8Stretchy Characters (15)3.9Matrices (16)3.10Accent Operators (16)3.11Differential, Exponential, and Imaginary Symbols (17)3.12Unicode Subscripts and Superscripts (18)3.13Concatenation Operators (18)3.14Comma, Period, and Colon (18)3.15Ordinary Text Inside Math Zones (19)3.16Space Characters (19)3.17Phantoms and Smashes (21)3.18Arbitrary Groupings (22)3.19Equation Arrays (22)3.20Math Zones (22)3.21Equation Numbers (23)3.22Linear Format Characters and Operands (23)3.23Equation Breaking and Alignment (26)3.24Size Overrides (26)4.Input Methods (27)4.1Character Translations (27)4.2Math Keyboards (29)4.3Hexadecimal Input (29)4.4Pull-Down Menus, Toolbars, Context Menus (29)4.5Macros (30)4.6Linear Format Math Autocorrect List (30)4.7Handwritten Input (30)5.Recognizing Mathematical Expressions (31)ing the Linear Format in Programming Languages (32)6.1Advantages of Linear Format in Programs (33)6.2Comparison of Programming Notations (34)6.3Export to TeX (36)7.Conclusions (37)Acknowledgements (37)Appendix A. Linear Format Grammar (38)Appendix B. Character Keywords and Properties (39)Version Differences (48)References (48)1.IntroductionGetting computers to understand human languages is important in increasing the utility of computers. Natural-language translation, speech recognition and gen-eration, and programming are typical ways in which such machine comprehension plays a role. The better this comprehension, the more useful the computer, and hence there has been considerable current effort devoted to these areas since the early 1960s. Ironically one truly international human language that tends to be ne-glected in this connection is mathematics itself.With a few conventions, Unicode1 can encode many mathematical expressions in readable nearly plain text. Technically this format is a “lightly marked up format”; hence the use of “nearly”. The format is linear, but it can be displayed in built-up presentation form. To distinguish the two kinds of formats in this paper, we refer to the nearly plain-text format as the linear format and to the built-up presentation format as the built-up format. This linear format can be used with heuristics based on the Unicode math properties to recognize mathematical expressions without the aid of explicit math-on/off commands. The recognition is facilitated by Unicode’s strong support for mathematical symbols.2Alternatively, the linear format can be used in “math zones” explicitly controlled by the user either with on-off characters as used in TeX or with a character format attribute in a rich-text environment. Use of math zones is desirable, since the recognition heuristics are not infallible.The linear format is more compact and easy to read than [La]TeX,3,4or MathML.5 However unlike those formats, it doesn’t attempt to include all typograph-ical embellishments. Instead we feel i t’s useful to handle some embellishments in the higher-level layer that handles rich text properties like text and background col-ors, font size, footnotes, comments, hyperlinks, etc. In principle one can extend the notation to include the properties of the higher-level layer, but at the cost of re-duced readability. Hence embedded in a rich-text environment, the linear format can faithfully represent rich mathematical text, whereas embedded in a plain-text environment it lacks most rich-text properties and some mathematical typograph-ical properties. The linear format is primarily concerned with presentation, but it has some semantic features that might seem to be only content oriented, e.g., n-aryands and function-apply arguments (see Secs. 3.4 and 3.5). These have been in-cluded to aid in displaying built-up functions with proper typography, but they also help to interoperate with math-oriented programs.Most mathematical expressions can be represented unambiguously in the line-ar format, from which they can be exported to [La]TeX, MathML, C++, and symbolic manipulation programs. The linear format borrows notation from TeX for mathe-matical objects that don’t lend themselves well to a mathematical linear notation, e.g., for matrices.A variety of syntax choices can be used for a linear format. The choices made in this paper favor a number of criteria: efficient input of mathematical formulae, suffi-cient generality to support high-quality mathematical typography, the ability to round trip elegant mathematical text at least in a rich-text environment, and a for-mat that resembles a real mathematical notation. Obviously compromises between these goals had to be made.The linear format is useful for 1) inputting mathematical expressions,6 2) dis-playing mathematics by text engines that cannot display a built-up format, and 3) computer programs. For more general storage and interchange of math expressions between math-aware programs, MathML and other higher-level languages are pre-ferred.Section 2 motivates and illustrates the linear format for math using the fraction, subscripts, and superscripts along with a discussion of how the ASCII space U+0020 is used to build up one construct at a time. Section 3 summarizes the usage of the other constructs along with their relative precedences, which are used to simplify the notation. Section 4 discusses input methods. Section 5 gives ways to recognize mathematical expressions embedded in ordinary text. Section 6explains how Unicode plain text can be helpful in programming languages. Section 7 gives conclu-sions. The appendices present a simplified linear-format grammar and a partial list of operators.2.Encoding Simple Math ExpressionsGiven Unicode’s strong support for mathematics2 relative to ASCII, how much better can a plain-text encoding of mathematical expressions look using Unicode? The most well-known ASCII encoding of such expressions is that of TeX, so we use it for comparison. MathML is more verbose than TeX and some of the comparisons ap-ply to it as well. Notwithstanding TeX’s phenomenal success in the science and engi-neering communities, a casual glance at its representations of mathematical expres-sions reveals that they do not look very much like the expressions they represent. It’s not easy to make algebraic calculations by hand directly using TeX’s notation. With Unicode, one can represent mathematical expressions more readably, and the resulting nearly plain text can often be used with few or no modifications for such calculations. This capability is considerably enhanced by using the linear format in a system that can also display and edit the mathematics in built-up form.The present section introduces the linear format with fractions, subscripts, and superscripts. It concludes with a subsection on how the ASCII space character U+0020 is used to build up one construct at a time. This is a key idea that makes the linear format ideal for inputting mathematical formulae. In general where syntax and semantic choices were made, input convenience was given high priority.2.1FractionsOne way to specify a fraction linearly is LaTeX’s \frac{numerator}{denominator}. The { } are not printed when the fraction is built up. These simple rules immediately give a “plain text” that is unambiguous, but looks quite different from the corre-sponding mathematical notation, thereby making it harder to read.Instead we define a simple operand to consist of all consecutive letters and decimal digits, i.e., a span of alphanumeric characters, those belonging to the L x and Nd General Categories (see The Unicode Standard 5.0,1 Table 4-2. General Category). As such, a simple numerator or denominator is terminated by most nonalphanumer-ic characters, including, for example, arithmetic operators, the blank (U+0020), and Unicode characters in the ranges U+2200..U+23FF, U+2500..U+27FF, and U+2900 .. U+2AFF. The fraction operator is given by the usual solidus / (U+002F). So the sim-ple built-up fractionabc d .appears in linear format as abc/d. To force a display of a normal-size linear fraction, one can use \/ (backslash followed by slash).For more complicated operands (such as those that include operators), paren-theses (), brackets [], or braces {} can be used to enclose the desired character combinations. If parentheses are used and the outermost parentheses are preceded and followed by operators, those parentheses are not displayed in built-up form, since usually one does not want to see such parentheses. So the plain text (a + c)/d displays asa+cd.In practice, this approach leads to plain text that is easier to read than LaTeX’s, e.g., \frac{a + c}{d}, since in many cases, parentheses are not needed, while TeX requires {}’s. To force the display of the outermost parentheses, one encloses them, in turn, within parentheses, which then become the outermost parentheses. For example, ((a + c))/d displays as(a+c).A really neat feature of this notation is that the plain text is, in fact, often a legit-imate mathematical notation in its own right, so it is relatively easy to read. Contrast this with the MathML version, which (with no parentheses) reads as<mfrac><mrow><mi>a</mi><mo>+</mo><mi>c</mi></mrow><mi>d</mi></mfrac>Three built-up fraction variations are available: the “fraction slash” U+2044 (which one might input by typing \sdiv) builds up to a skewed fraction, the “division slash” U+2215 (\ldiv) builds up to a potentially large linear fraction, and the circled slash ⊘ (U+2298, \ndiv) builds up a small numeric fraction (although characters other than digits can be used as well). The three kinds of built-up fractions are illus-trated byab+c de+f ,ab+cde+f⁄,(ab+c)(de+f)⁄When building up the large linear fraction, the outermost parentheses should not be removed.The same notational syntax is used for a “stack” which is like a fraction with no fraction bar. The stack is used to create binomial coefficients and the stack operator is ‘¦’ (\atop). For example, the binomial theorem(a+b)n=∑(nk)a k b n−knk=0in linear format reads as (see Sec. 3.4 for a discussion of the n-aryand “glue” opera-tor ▒)(a + b)^n = ∑_(k=0)^n▒ (n ¦ k) a^k b^(n-k),where (n ¦ k) is the binomial coefficient for the combinations of n items grouped k at a time. The summation limits use the subscript/superscript notation discussed in the next subsection.Since binomial coefficients are quite common, TeX has the \choose control word for them. In the linear format Version 3, this uses the \choose operator ⒞in-stead of the \atop operator ¦. Accordingly the binomial coefficient in the binomial theorem above can be written as “n\choose k”, assuming that you type a space after the k. This shortcut is included primarily for compatibility with TeX, since (n¦k) is pretty easy to type.When / is followed by an operator, it’s highly unlikely that a fraction is intend-ed. This fact leads to a simple way to enter negated operators like ≠, namely, justtype /= to get ≠. A list of such negated operator combinations is given in Section 4.1. To enter ≠, you can also type TeX’s name, \ne, but /= is slightly simpler. And the TeX names for the other negated operators in Section 4.1 are harder to remember. One other trick with fractions is that a period or comma in between two digits or in be-tween the slash and a digit is considered to be part of a number, rather than being a terminator. For example 1/3.1416 builds up to 13.1416, rather than 13.1416.2.2 Subscripts and SuperscriptsSubscripts and superscripts are a bit trickier, but they’re still quite readable. Specifically, we introduce a subscript by a subscript operator, which we display as the ASCII underscore _ as in TeX. A simple subscript operand consists of the string of one or more characters with the General Categories L x (alphabetic) and Nd (decimal digits), as well as the invisible comma. For example, a pair of subscripts, such as δ is written as δ_μν. Similarly, superscripts are introduced by a superscript operator, which we display as the ASCII ^ as in TeX. So a ^b means a b . A nice enhancement for a text processing system with build -up capabilities is to display the _ as a small sub-script down arrow and the ^ as a small superscript up arrow, in order to convey the semantics of these build -up operators in a math context.Compound subscripts and superscripts include expressions within parenthe-ses, square brackets, and curly braces. So δ is written as δ_(μ+ν). In addition it is worthwhile to treat two more operators, the comma and the period, in special ways. Specifically, if a subscript operand is followed directly by a comma or a period that is, in turn, followed by whitespace, then the comma or period appears on line, i.e., is treated as the operator that terminates the subscript. However a comma or period followed by an alphanumeric is treated as part of the subscript. This refine-ment obviates the need for many overriding parentheses, thereby yielding a more readable linear -format text (see Sec. 3.14 for more discussion of comma and period).Another kind of compound subscript is a subscripted subscript, which works using right -to -left associativity, e.g., a_b_c stands for a b c . Similarly a ^b ^c stands for a b c .Parentheses are needed for constructs such as a subscripted superscript like a b c , which is given by a ^(b_c ), since a ^b_c displays as a c b (as does a _c ^b ). The build -up program is responsible for figuring out what the subscript or superscript base is. Typically the base is just a single math italic character like the a in these examples. But it could be a bracketed expression or the name of a mathematical function like sin as in sin^2 x , which renders as sin 2x (see Sec. 3.5 for more discussion of this case). It can also be an operator, as in the examples +1 and =2. In Indic and other clus-ter -oriented scripts the base is by default the cluster preceding the subscript or su-perscript operator.As an example of a slightly more complicated example, consider the expression W δ1ρ1σ23β, which can be written with the linear format W^3β_δ1ρ1ς2, where Unicode numeric subscripts are used. In TeX, one types$W^{3\beta}_{\delta_1\rho_1\sigma_2}$The TeX version looks simpler using Unicode for the symbols, namely $W^{3β}_{δ_1 ρ_ς_2}$ or $W^{3β}_{δ1ρ1ς2}$, since Unicode has a full set of decimal subscripts and superscripts. As a practical matter, numeric subscripts are typically entered using an underscore and the number followed by a space or an operator, so the major simpli-fication is that fewer brackets are needed.For the ratio α23β23+γ23 the linear -format text can read as α₂³/( β₂³ + γ₂³), while the standard TeX version reads as$$\alpha_2^3 \over \beta_2^3 + \gamma_2^3$$·The linear -format text is a legitimate mathematical expression, while the TeX ver-sion bears no resemblance to a mathematical expression.TeX becomes cumbersome for longer equations such asW δ1ρ1σ23β=U δ1ρ13β+12∫dα2′[U δ1ρ12β−α2′U ρ1σ21βU ρ1σ2]α2α1 A linear -format version of this reads asW_δ1ρ1ς2^3β=U_δ1ρ1^3β+1/8π^2 ∫_α1^α2▒dα’2 [(U_δ1ρ1^2β-α’2U_ρ1ς2^1β)/U_ρ1ς2^0β]while the standard TeX version reads as$$W_{\delta_1\rho_1\sigma_2}^{3\beta}= U_{\delta_1\rho_1}^{3\beta} + {1 \over 8\pi^2}\int_{\alpha_1}^{\alpha_2} d\alpha_2’ \left[{U_{\delta_1\rho_1}^{2\beta} - \alpha_2’U_{\rho_1\sigma_2}^{1\beta} \overU_{\rho_1\sigma_2}^{0\beta}} \right] $$ .2.3 Use of the Blank (Space) CharacterThe ASCII space character U+0020 is rarely needed for explicit spacing of built-up text since the spacing around operators should be provided automatically by the math display engine (Sec. 3.16 discusses this automatic spacing). However the space character is very useful for delimiting the operands of the linear-format notation. When the space plays this role, it is eliminated upon build up. So if you type \alphafollowed by a space to get α, the space is eliminated when the α replaces the \alpha. Similarly a_1 b_2 builds up as a1b2 with no intervening space.Another example is that a space following the denominator of a fraction is eliminated, since it causes the fraction to build up. If a space precedes the numerator of a fraction, the space is eliminated since it may be necessary to delimit the start of the numerator. Similarly if a space is used before a function-apply construct (see Sec.3.5) or before above/below scripts (see Sec. 3.3), it is eliminated since it delimits the start of those constructs.In a nested subscript/superscript expression, the space builds up one script at a time. For example, to build up a^b^c to a b c, two spaces are needed if spaces are used for build up. Some other operator like + builds up the whole expression, since the operands are unambiguously terminated by such operators.In TeX, the space character is also used to delimit control words like \alpha and does not appear in built-up form. A difference between TeX’s usage and the lin-ear format’s is that in TeX, blanks are invariably eliminated in built-up display, whereas in the linear format blanks that don’t delimit operands or keywords do re-sult in spacing. Additional spacing characters are discussed in Sec. 3.16.One displayed use for spaces is in overriding the algorithm that decides that an ambiguous unary/binary operator like + or − is unary. If followed by a space, the operator is considered to be binary and the space isn’t displayed. Spaces are also used to obtain the correct spacing around comma, period, and colon in various con-texts (see Sec. 3.14).3.Encoding Other Math ExpressionsThe previous section describes how we encode fractions, subscripts and super-scripts in the linear format and gives a feel for that format. The current section de-scribes how we encode other mathematical constructs using this approach and ends with a more formal discussion of the linear format.3.1DelimitersBrackets [], braces {}, and parentheses () represent themselves in the Unicode plain text, and a word processing system capable of displaying built-up formulas should be able to enlarge them to fit around what’s inside them. In general we refer to such characters as delimiters. A delimited pair need not consist of the same kinds of delimiters. For example, it’s fine to open with [ and close with } and one sees this usage in some mathematical documents. The closing delimiter can have a subscript and/or a superscript. Delimiters are called fences in MathML.These choices suffice for most cases of interest. But to allow for use of a delim-iter without a matching delimiter and to overrule the open/close character of delim-iters, the special keywords \open and \close can be used. These translate to the box-drawings characters├ and ┤, respectively. Box drawings characters are used for theopen/close delimiters because they aren’t likely to be used as mathematical charac-ters and they are readily available in fonts. If used before any character that isn’t a delimiter of the opposite sense, the open/close delimiter acts as an invisible delimit-er, defining the corresponding end of a delimited expression. A common use of this is the “cases” equation, such as,|x|={x if x≥ 0−x if x<0which has the linear format “|x| = {█ (&x" if "x ≥ 0@−&x" if "x < 0)┤" (see Sec. 3.19 for a discussion of the equation-array operator █ ).Because the cases construct is fairly common, TeX has the \cases control word for it. This can be implemented in the linear format Version 3 with the \cases opera-tor Ⓒ. With this the equation above can be written as “|x| = Ⓒ(&x" if "x ≥ 0@−&x" if "x < 0)", which is still a little strange, but you don’t have to type the opening curly brace and \close.The open/close delimiters can be used to overrule the normal open/close character of delimiters as in the admittedly strange, but nevertheless sometimes used, expression “]a + b[”, which has the linear format “├]a+b┤[”. Note that a blank following an open or close delimiter is “eaten”. This is to allow an open delimiter to be followed by a normal delimiter without interpreting the pair as a single delimiter. See also Sec. 3.18 on how to make arbitrary groupings. If a├ needs to be treated as an empty open delimiter when it appears before a delimiter like | or ], follow the├by a space to force the open-delimiter interpretation.To suppress automatic sizing and to choose specific sizes,├is followed by a digit ‘0’ –‘4’ with the meanings in the following tableIt’s rarely necessary to use explicit sizes if the display system can break equations within bracketed expressions.The usage of open and close delimiters in the linear format is admittedly a compromise between the explicit nature of TeX and the desire for a legitimate math notation, but the flexibility can be worth the compromise especially when interoper-ating with ordinarily built-up text such as in a WYSIWYG math system. TeX uses \left and \right for this purpose instead of \open and \close. We use the latter since they apply to right-to-left mathematics used in many Arabic locales as well as to the usual left-to-right mathematics.Absolute values are represented by the ASCII vertical bar | (U+007C). The evenness of its count at any given bracket nesting level typically determines whetherthe vertical bar is a close |. Specifically, the first appearance is considered to be anopen | (unless subscripted or superscripted), the next a close | (unless following anoperator), the next an open |, and so forth.Nested absolute values can be handled unambiguously by discarding theoutermost parentheses within an absolute value. For example, the built-up expres-sion ||x| - |y|| can have the linear format |(|x|−|y|)|. Some cases, such as this one, can be parsed without the clarifying parentheses by noting that a vertical bar | directlyfollowing an operator is an open |. But the example |a|b−c|d| needs the clarifying pa-rentheses since it can be interpreted as either (|a|b)−(c|d|) or |a(|b−c|)d|. The usualalgorithm gives the former, so if one wants the latter without the inner parentheses,one can type |(a|b−c|d)|.Another case where we treat | as a close delimiter is if it is followed by a space(U+0020). This handles the important case of the bra vector in Dirac notation. Forexample, the quantum mechanical density operator ρ has the definition,ρ=∑Pψ|ψ⟩⟨ψ|ψwhere the vertical bars can be input using the ASCII vertical bar.If a | is followed by a subscript and/or a superscript and has no correspondingopen |, it is treated as a script base character, i.e., not a delimiter. Its built-up sizeshould be the height of the integral sign in the current display/inline mode.The Unicode norm delimiter U+2016 (‖ or \norm) has the same open/closedefinitions as the absolute value character | except that it’s always considered to be adelimiter.Delimiters can also have separators within them. Version 2 of the linear formatdoesn’t formalize the comma separators of function arguments (MathML does), butit supports the vertical bar separator \vbar, which is represented by the box draw-ings light vertical character│(U+2502). We tried using the ASCII | (U+007C) for this purpose too, but the resulting ambiguities are insurmountable in general. One case using U+007C as a separator that can be deciphered is that of the form (a|b), where a and b are mathematical expressions. But (a|b|c) interprets the vertical bars as the absolute value. And one might want to interpret the | in (a|b) as an open delimiter with ) as the corresponding close delimiter, while the ( isn’t yet matched. If so, pre-cede the | by├, i.e., (├|b). The vertical bar separator grows in size to match the size of the surrounding brackets. In Version 3, other operators can be treated as separa-tors by preceding them with \middle (║— U+2551).Another common separator is the \mid character ∣ (U+2223), commonly usedin expressions like {x | f(x)=0}. This separator also grows in size to match the sur-rounding brackets and is spaced as a relational operator.3.2Literal OperatorsCertain operators like brackets, braces, parentheses, superscript, subscript, in-tegral, etc., have special meaning in the linear-format notation. In fact, even a charac-ter like ‘+’, which displays the same glyph in linear format as in built-up form (aside from a possible size reduction), plays a role in the linear format in that it terminates an operand. To remove the linear-format role of such an operator, we precede it by the “literal operator”, for which the backslash \ is handy. So \[ is displayed as an or-dinary left square bracket, with no attempt by the build-up software to match a cor-responding right square bracket. Such quoted operators are automatically included in the current operand.Linear format operators always consist of a single Unicode character, although a control word like \open may be used to input the character. Using a single charac-ter has the advantage of being globalized, since the control word typically looks like English. Users can define other control words that look like words in other lan-guages just so long as they map into the appropriate operator characters. A slight exception to the single-character operator rule occurs for accent operators that are applied to two or more characters (see Sec. 3.10). For these the accent combining mark may be preceded by a no-break space for the sake of readability. Another ad-vantage of using operator characters rather than control words is that the build-up processing is simplified and therefore faster. And one should delight in the fact that the operator characters look like the operators they represent, while the control words do not.3.3Prescripts and Above/Below ScriptsA special parenthesized syntax is used to form prescripts, that is, subscripts and superscripts that precede their base. For this (_c^b)a creates the prescripted variable a c b. Variables can have both prescripts and postscripts (ordinary subscripts and superscripts).In Version 3 of the linear format, you can use a prescript notation similar to TeX’s. Just type a subscript and/or a superscript not preceded by a base and then follow it with a character that can be used as a base. For the c b a example, you type _c^b a. Note that you need to terminate the superscript with a space. If a variable precedes the prescript, you also need to precede the prescript with a space. A com-mon use of prescripts is for the confluent hypergeometric functions, such as F11. In Version 3, this can be input as _1 F_1 or as (_1^)F_1.Below scripts and above scripts are represented in general by the line drawing operators \below (┬) and \above (┴), respectively. Hence the expression im n a n can be represented by lim┬ (n→∞) a_n. Since the operations det, gcd, inf, lim, lim inf, lim sup, max, min, Pr, and sup are common, their below scripts are also accessible by the usual subscript operator _. So in display mode, im n a n can also be represented by lim_(n→∞) a_n, which is a little easier to type than lim┬(n→∞) a_n.Although for illustration purposes, the belowscript examples are shown here in-line with the script below, ordinarily this choice is only for display-mode math. When inline, below- and abovescripts entered with _ and ^ are shown as subscripts。

a useful skill.英语作文全文共6篇示例，供读者参考篇1A Useful SkillHi there! My name is Emma, and I'm a 10-year-old student in the fifth grade. Today, I want to share with you a very cool and useful skill that I've learned recently – coding!You might be wondering, "What is coding, and why is it so important?" Well, let me tell you all about it!Coding is like a secret language that we use to communicate with computers and tell them what to do. It's a bit like giving instructions to a friend, but instead of telling them to do something like "Clean your room," you're telling the computer to perform specific tasks or create amazing things like websites, games, and apps.At first, coding might seem a bit confusing and complicated, but once you get the hang of it, it's actually really fun and exciting! It's like solving puzzles or playing a game – you have tothink logically and creatively to make the code work the way you want it to.In my school, we started learning coding last year, and I quickly fell in love with it! We used a cool program called Scratch, which is designed specifically for kids like me to learn coding in a fun and interactive way. With Scratch, you can create your own animations, games, and stories by dragging and dropping different blocks of code together, like building blocks.One of the first projects I worked on was creating a simple game where a cat had to catch falling mice. I had to program the cat to move left and right, make the mice fall from the top of the screen, and keep track of the score. It was a bit tricky at first, but with the help of my teacher and some practice, I eventually got it working perfectly!Since then, I've created all sorts of cool projects using Scratch, like an animated story about a superhero, a virtual pet that you can feed and play with, and even a simple version of the classic game "Pong." Each project challenged me to think in new ways and use different coding concepts, like loops, conditional statements, and variables.But coding isn't just about making fun games and animations – it's also a really valuable skill that can help us in somany other areas of life. For example, coding teaches us how to break down big problems into smaller, more manageable steps, which is really useful for problem-solving in general.It also helps us develop our logical thinking and creativity, as we have to come up with efficient and innovative solutions to make our code work properly. Plus, learning to code at a young age can open up all sorts of exciting career opportunities in the future, like becoming a software developer, a game designer, or even a robotics engineer!One of the things I love most about coding is that it's a skill that anyone can learn, no matter their age or background. It's like learning a new language – the more you practice and immerse yourself in it, the better you'll become.Another great thing about coding is that it's a constantly evolving field, with new languages, tools, and technologies emerging all the time. This means that there's always something new to learn and explore, which keeps things exciting and interesting.For example, just recently, my teacher introduced us to a new coding platform called Python, which is a more advanced and powerful language used by professional programmers. It's definitely more complex than Scratch, but I'm really lookingforward to learning it and seeing what amazing things I can create with it.So, if you're a kid like me and you haven't tried coding yet, I highly recommend giving it a shot! It might seem a bit daunting at first, but trust me, it's incredibly rewarding and fun once you get the hang of it.And who knows? Maybe someday, you'll be the one creating the next big app, game, or piece of software that changes the world!That's all for now, folks! Happy coding, and remember – the possibilities are endless when you can speak the language of computers!篇2A Useful SkillHi everyone! Today I want to talk about a really cool skill that I think is super useful. It's something that can help us in many different situations. Can you guess what it is? Yes, it's the skill ofproblem-solving!Problem-solving is like being a detective. You get to solve mysteries and find solutions to different problems. It's like a superpower that we all have inside us. Let me tell you why it's such an important skill to have.First of all, problem-solving helps us think creatively. When we face a problem, we need to come up with new ideas and think outside the box. For example, imagine you're doing a puzzle and you can't find a piece that fits. What do you do? You might try different pieces and look at the shapes and colors until you find the right one. This kind of creative thinking helps us find solutions to all kinds of problems in our daily lives.Secondly, problem-solving teaches us to be patient. Sometimes, finding a solution takes time and effort. We might not get it right the first time, but that's okay! We learn from our mistakes and keep trying until we succeed. Just like when we learn to ride a bike or play a musical instrument, it takes practice and patience to become good at problem-solving.Another reason why problem-solving is important is that it helps us become better at working with others. When we face a difficult problem, we can ask for help from our friends, teachers, or family members. By listening to their ideas and working together, we can find solutions faster and learn from each other.It's like being a team, where everyone brings their unique skills to solve a problem together.Moreover, problem-solving makes us more independent. When we can find solutions on our own, we become more confident and self-reliant. We don't always need someone else to fix our problems for us. We can take charge and find our own solutions. This is a really important skill to have as we grow up and face bigger challenges in life.In conclusion, problem-solving is a really useful skill that we should all learn. It helps us think creatively, be patient, work with others, and become more independent. So, let's embrace our inner problem-solvers and remember that every problem is just an opportunity to learn and grow. Keep solving those puzzles, my friends!I hope you enjoyed reading my essay. Remember, problem-solving is a skill that will always come in handy. Keep practicing and never stop being curious!篇3A Useful SkillHi everyone! Today, I want to tell you about a really cool skill that I think is super useful. It's something that can help you in many different situations, and it's called "problem-solving". So, let's dive in and learn more about this amazing skill!Problem-solving is like being a detective. You have to use your brain to figure out solutions to difficult problems. It's like putting together the pieces of a puzzle. Sometimes things don't go the way we want them to, and that's when problem-solving comes in handy.One important thing to remember is that problem-solving is not just for adults. Even us kids can be great problem-solvers! We face problems every day, whether it's figuring out a math problem or finding a lost toy. Problem-solving helps us become independent and confident individuals.Let me share a story to show you how problem-solving can make a big difference. Once upon a time, there was a little girl named Lily. She loved playing outside with her friends, but one day she realized that her favorite swing was broken. Lily was really sad because she couldn't swing anymore.Instead of feeling down, Lily decided to use herproblem-solving skills. First, she observed the swing carefully to understand what was wrong. She noticed that one of the chainswas broken. Next, she brainstormed different solutions. She thought about asking her dad to fix it, but he was at work. Then she thought about using her own tools, but she didn't have any.Finally, Lily came up with an idea. She remembered that her neighbor, Mr. Johnson, was really good at fixing things. She went to his house and explained the problem. Mr. Johnson was happy to help and together they fixed the swing. Lily was overjoyed and grateful for her problem-solving skills.Problem-solving is not only about fixing broken things, it's also about finding creative solutions to everyday challenges. For example, let's say you have a big pile of toys in your room and it's a mess. Instead of feeling overwhelmed, you can use problem-solving to come up with a plan. You can start by organizing the toys into different categories or create a system to keep them tidy. Before you know it, your room will be clean and you'll feel proud of yourself!Another great thing about problem-solving is that it helps us think critically. It encourages us to ask questions, think outside the box, and find multiple solutions to a problem. This skill is not only useful in school but also in our future careers. Employers love people who can think on their feet and find creative solutions to challenges.In conclusion, problem-solving is a super useful skill that we can all develop, no matter how young we are. It helps us become independent, confident, and resourceful individuals. So, let's embrace problem-solving and tackle any challenge that comes our way. Remember, you have the power to be an amazing problem-solver!I hope you enjoyed reading my essay. Keep practicing problem-solving, and you'll be amazed at what you can achieve.篇4A Useful SkillHave you ever wondered what skill you should learn that would be really useful? Well, I've been thinking about it a lot lately and I've decided the most useful skill is cooking! Learning to cook is an awesome superpower that can help you in so many ways.First of all, knowing how to cook means you'll always be able to make yourself delicious food. You won't have to rely on your parents or just eat frozen meals or fast food all the time. Being able to cook lets you eat fresh, healthy meals that actually taste good. My friend Jacob's mom is an amazing cook and whenever Igo over to his house for dinner, the food is so yummy. It makes me really want to learn her secrets!Another great thing about cooking is you can make your favorite foods exactly how you like them. Like if you really love pizza but want it with extra cheese and pepperoni, you can make it that way instead of just ordering from the same old pizza place. Or if you're craving mom's spaghetti and meatballs but she's too busy to cook, you can whip it up yourself. Knowing how to cook gives you so much more control over what you eat.But cooking isn't just about the food itself. It's also a fun activity and a way to get creative. You can experiment with different ingredients and flavors to come up with your own unique recipes. It's like being a chef or a scientist in a kitchen laboratory! My older sister loves baking and she's always making up these crazy delicious cupcake and cookie flavors. I want to be able to do that kind of stuff too.Cooking also helps you learn about different cultures around the world. Each country and region has its own special cuisine with distinct dishes, flavors, and cooking techniques. By learning to make those foods, you can experience and appreciate cultures through your taste buds! How cool would it be to make your own homemade sushi, falafel, enchiladas, or beef bourguignon?It's like taking a culinary vacation without even leaving your kitchen.Plus, cooking is a useful life skill that will help you out forever. If you go to college, you'll be able to cook decent meals for yourself instead of just eating ramen every day. When you have your own place, you can save tons of money by cooking at home instead of ordering out or going to restaurants all the time. And if you have a family someday, you can make healthy, delicious meals for your kids so they grow up loving good food.But in my opinion, putting in the effort to learn cooking is totally worth it. It's such a valuable skill that you'll literally use your whole life. Being able to cook lets you eat amazing food while being creative, learning about the world, and taking care of yourself. What other skill gives you that many awesome benefits?So if you ask me, cooking is hands-down the most useful skill a kid can learn. It combines art, science, culture, and survival all into one highly delicious skillset. I've already been bugging my parents to start teaching me and they say as soon as I master safety stuff like not touching hot surfaces, they'll let me help out more in the kitchen. I can't wait! Being able to cook is like having a superpower, and I'm determined to become a KitchenSuperhero. Now if you'll excuse me, I need to go study some recipes. Later!篇5A Useful Skill: How to Bake Delicious CookiesHi there! My name is Emma, and I'm 10 years old. Today, I want to tell you about one of the most useful skills I've learned –baking cookies! Baking is lots of fun, and it's a skill that will serve you well for your whole life. Once you know how to bake, you can make all sorts of delicious treats for yourself, your family, and your friends. And who doesn't love freshly baked cookies?!The first step in baking cookies is gathering all the ingredients and equipment you'll need. For chocolate chip cookies, you'll need things like flour, sugar, butter, eggs, baking soda, vanilla extract, and of course, chocolate chips. You'll also need basic baking equipment like mixing bowls, measuring cups and spoons, a wooden spoon, baking sheets, and an oven mitt.Once you have everything ready, it's time to start mixing! The very first thing you do is preheat the oven to the right temperature, which for this recipe is 375°F or 190°C. While the oven is heating up, you can start combining the dry ingredients like flour, baking soda, and salt in one bowl. In another bowl,you'll cream together the butter and sugars until it's nice and fluffy. Then you'll beat in the eggs one at a time, followed by the vanilla extract.Now it's time to combine the wet and dry ingredients by slowly mixing the dry mixture into the wet mixture. Be careful not to over-mix! Once it's just combined, you can gently fold in the chocolate chips. The dough should be thick and slightly sticky.Next, you'll need to scoop rounds of dough onto an ungreased baking sheet, spacing them a couple inches apart. Depending on how big you make the dough balls, this recipe should make around 2-3 dozen cookies. Before baking, I like to press a few extra chocolate chips into the tops of the dough balls for extra chocolate goodness!Now the hard part – you have to wait while the cookies bake for 8-10 minutes in the preheated oven. Try not to open the oven door too much, or your cookies might not bake evenly. When they're just starting to turn golden brown on the edges, take them out and let them cool on the baking sheet for 5 minutes before transferring to a wire rack. This is the toughest part because they'll smell sooooo good!Once the cookies are cooled, it's finally time to enjoy your hard work! Grab a glass of cold milk and take that first deliciousbite. The chocolate chips should still be melty, the centers should be soft and chewy, and the edges will have a perfect crunch. Mmmmm, I'm getting hungry just thinking about it!Baking cookies is a super useful skill because you'll always have a special homemade treat to share with others. You can bake cookies for birthday parties, holidays, or just because. Chocolate chip is my favorite, but once you master this basic recipe, you can play around with different flavors and mix-ins like peanut butter, oatmeal raisin, white chocolate macadamia nut, or whatever sounds good to you!Another great thing about knowing how to bake is that it teaches you to follow instructions carefully. Baking is a science, so you have to measure ingredients precisely and follow all the steps in order for your baked goods to turn out right. It's also a fun way to learn fractions when you're measuring out portions of cups and tablespoons. Who knew baking could be so educational?!I really encourage all of you to ask a parent or trusted adult to teach you how to bake cookies or any other treats. It's an incredibly useful skill that you'll be able to enjoy for the rest of your life. And whenever you bake, make sure to save me one (orfive)! There's nothing better than a warm, homemade, chocolate chip cookie straight from the oven. Yum!篇6A Useful SkillHi everyone! Today, I want to share with you all about a very useful skill that I have learned. It's called "Problem Solving". Let me tell you why it's important and how it has helped me in many different situations.Problem Solving is the ability to find solutions to difficult or challenging problems. It's like being a detective, trying to solve a mystery! This skill is important because it helps us overcome obstacles and make good decisions.One way I use problem-solving skills is when I'm doing my homework. Sometimes, I get stuck on a math problem or I don't understand a word in my reading assignment. Instead of giving up or asking for help right away, I try to think of different ways to solve the problem on my own. I might break the problem down into smaller steps or look up the meaning of the word in a dictionary. By using problem-solving skills, I can figure things out by myself and feel proud of my achievements!Problem Solving is not just useful for schoolwork, but also in everyday life. Let me give you an example. One day, I was playing with my friends in the park when we noticed a ball stuck in a tree. It was too high for us to reach. Instead of being disappointed, we put our problem-solving skills to work. We found a long stick and used it to gently nudge the ball until it fell down. We were so happy and proud of ourselves for solving the problem together!Another important aspect of problem-solving is making good decisions. Sometimes, we have to choose between different options and it can be tough. For instance, when I go to the supermarket with my mom, we have to decide what groceries to buy. I use my problem-solving skills to think about what we need, compare prices, and make choices that are healthy and within our budget. It's like being a little detective in the grocery store!In conclusion, problem-solving is a very useful skill for all of us, even as young students. It helps us overcome challenges, think critically, and make good decisions. Whether it's solving math problems, fixing a small issue, or making choices, problem-solving skills are always there to guide us. So, let's embrace this skill and become little problem-solving detectives in our own lives!Remember, no problem is too big or small for us to solve. We just need to believe in ourselves and think creatively. So, let's go out there and become amazing problem solvers!I hope you enjoyed reading my essay. Thank you!。

谈谈你对开设劳动课的看法英语作文全文共5篇示例，供读者参考篇1Here's an essay about my thoughts on having labor classes in school, written from the perspective of a elementary school student in around 2,000 words:My Thoughts on Having Labor Classes at SchoolHi there! My name is Timmy and I'm a 4th grader at Oakwood Elementary School. Today, I want to share my thoughts about having labor classes at our school. Labor classes are where we learn skills like woodworking, gardening, cooking, and sewing. Some people think they're really important, while others think they're a waste of time. I have some opinions about it that I want to share with you!First of all, I think labor classes are super fun! In woodworking class, we get to use all sorts of cool tools like saws, hammers, and drills. We've made birdhouses, picture frames, and even a big wooden bench for the school garden. It's amazing to start with a plain piece of wood and create something useful by the end of class. I really enjoy it!Gardening class is also a blast. We have our own little garden plot behind the school where we grow fruits, veggies, and flowers. Getting dirt under my nails doesn't bother me at all. I love watching the plants sprout up from the seeds we planted weeks earlier. It's so satisfying to nibble on a crisp carrot or juicy strawberry that you grew all by yourself. Gardening has taught me to be patient and care for living things. Plus, it's a nice break from sitting at a desk all day.Now, I'll admit that cooking and sewing classes aren't my absolute favorites. Trying to neatly sew a button onto a piece of fabric or follow a recipe precisely can be quite frustrating for me sometimes. But I know those skills will still come in handy when I'm older and living on my own. At least the sewing projects are better than the awful sweater my grandma made me last year! And who doesn't love eating the tasty treats we bake in cooking class?More importantly than just being fun, labor classes teach us valuable life skills. Sure, we learn lots of important stuff like math, science, and reading in our other classes. But labor classes give us hands-on experience with tools and tasks we'll actually use as grownups. Knowing how to cook a decent meal, sew a rippedseam, or build a shelf is way more useful than finding the square root of 196 if you ask me!I truly believe these classes make us more self-sufficient, hardworking, and resourceful young people. It's easy to take for granted all the hard work that goes into making the clothes we wear, preparing the food we eat, or constructing the buildings we live in. After a labor class though, you really appreciate just how much effort and skills go into creating those things. You learn not to be so wasteful and to take care of your belongings when you've made them yourself.Most importantly though, labor classes keep us from becoming couch potatoes who just lie around watching TV or playing video games all day. Don't get me wrong, I love my Nintendo Switch and cartoon shows as much as the next kid. But it's so unhealthy to never use your hands and body to actually create tangible things. These classes get us up and moving instead of being glued to a screen for hours on end. You get steps in, you work up a sweat, and you engage your brain in a different way by problem-solving with your hands. That's got to be better for our health than just sitting there like a lump.Now, I know some people argue that labor classes are outdated and we should focus more on STEM stuff like codinginstead. To those people, I say labor classes absolutely teach important STEM skills too! Have you ever had to measure precisely in woodworking, carefully follow the steps of a recipe, or use geometry to frame a garden bed? You use math, science, engineering and technology all the time in these classes, just in a different hands-on way.People also complain that labor classes are tooold-fashioned or politically incorrect. For example, some think cooking and sewing are sexist because they promote outdated gender roles of women belonging in the kitchen and doing housework. Or that woodworking and gardening are for farmers and uneducated people. Those are really ignorant viewpoints in my opinion.First of all, cooking healthy meals and basic sewing are skills that everybody needs to know how to do, regardless of your gender or future job. Why should those just be "women's work"? Lots of famous male chefs and fashion designers are amazing at those too. And woodworking and gardening aren't just for country bumpkins - those skills allow you to build and grow stuff yourself instead of buying everything from stores. It's the opposite of uneducated - you have to learn specific knowledge and techniques to do them well. Plus, labor classes show us thatthere's value and dignity in all kinds of work, not just fancy office jobs.At the end of the day, I'm really grateful that our school has labor classes as part of our curriculum. They teach us so many valuable hands-on abilities outside of just academics. They help us appreciate the craftsmanship behind ordinary things we take for granted. Most importantly though, they get us actively working with our hands and bodies rather than being sedentary all day. That's way better for our health and making uswell-rounded, capable people.I truly believe labor classes make us into resourceful problem-solvers who can tackle any task with confidence. Yeah, they may require more effort and get your hands a bit grubby sometimes. But that's something to be proud of, not ashamed of! We shouldn't just sit in a classroom listening to lectures all day. Getting outdoors, handling tools, and creating useful objects with our own hands is an amazing way to learn. I really hope labor classes stick around for a long, long time.篇2My Views on Having a Labor ClassHi everyone! My name is Emma and I'm 10 years old. I go to Oakwood Elementary School. Today I want to talk to you about having a labor class at school. This is something my school started doing last year and I have some thoughts about it that I want to share.First off, what even is a labor class? Well, it's a class where instead of sitting at desks and doing bookwork, we actually learn skills by doing hands-on work and projects. In my labor class, we've done all sorts of different things like woodworking, gardening, sewing, cooking, and basic repairs around the school. I've made a sweet little wooden box, grown my own tomato plant, sewn a tote bag, baked cookies, and fixed a wobbling chair leg. It's awesome!I think having a labor class is really really great for lots of reasons. One big reason is that it teaches us important life skills that we'll definitely need when we're adults and have our own homes someday. Like if I ever need to do simple repairs, cook meals, or work on projects around the house, I'll already know how instead of being totally clueless. The class makes us more capable and independent.Another amazing thing about labor class is that it gets us moving around and working with our hands instead of justsitting at a desk all day. Sitting too much isn't good for kids! In labor class, we're active and it helps us burn off energy in a productive way. It's a nice break from all the book stuff we do the rest of the day.I also love labor class because it's just really fun! It feels like playtime in a way, but we're still learning. Getting to use tools, get messy with soil and paint, and make cool projects is so enjoyable. Regular school can be kind of boring with all the reading and math practice. But labor class is exciting!One of my favorite parts is that we often get to work together in teams to do bigger projects. We learn cooperation, communication, and teamwork skills that way. Like if we're building a big structure out of wood, we have to collaborate, assign roles, help each other out, and talk about the plan. Those are crucial abilities to practice.Labor class also sparks creativity by letting us design and make things however we want. With the woodworking projects, I can choose what box or sculpture to make and how to decorate it. When we cook, we can experiment with different ingredients. This encourages our imagination and inventiveness.I've noticed that labor class helps a lot of different kids shine in a way they don't in other classes too. For students whostruggle with reading, writing, and sitting still, this class allows them to excel at hands-on skills. It makes them feel capable instead of frustrated or bored. And kids who are creative or more physical get a chance to put those strengths to use.Overall, having a labor class is fantastic in my opinion. It prepares us for real life, gets our bodies moving, makes learning entertaining, builds teamwork abilities, boosts creativity, and lets kids show their diverse talents. Every school should have a class like this!Of course, no class is perfect and there are a couple small downsides to labor class. One is that it can get pretty messy with all the hands-on work we do. We track in dirt, slop paint around, and make crumbs from cooking. Having to clean up at the end is a hassle. But getting messy is part of the fun too!Another negative is that we can't have labor class more than once a week since it requires a lot of materials, time, and space. It's disappointing only getting that class once a week when I enjoy it so much. But I guess you can't have too many good things.Despite those minor issues, labor class has been an awesome addition to my school's curriculum. I look forward to it every week and I'm learning so many practical skills that willbenefit me forever. I hope every kid gets the chance to take a labor class like mine while growing up. It makes school much more worthwhile and applicable to real life.Thanks for reading about my thoughts on labor class! Let me know if you have any other questions. I'll be over here working on a cool birdhouse woodworking project. See ya!篇3My Thoughts on Having a Labor ClassHi there! My name is Timmy and I'm in the 5th grade. My teacher Mrs. Roberts told our class that starting next year, we're going to have a new class called "Labor Class." I wasn't really sure what that meant at first, but she explained it's a class where we'll learn all about different kinds of jobs and work. We'll even get to do some hands-on projects and activities related to different careers. I thought that sounded pretty neat!A lot of my classmates got really excited when they heard about Labor Class. My best friend Michael said he can't wait because he wants to learn about being a construction worker like his dad. Maria raised her hand and said she's interested in learning more about working on cars and trucks because heruncle is a mechanic. It seemed like everybody had some job in mind that a family member does that they wanted to explore.For me, I'm really curious to learn about lots of different jobs. My parents both work at an office, so I don't know much about other types of careers. I'd love to learn what bakers, police officers, scientists, and all sorts of other workers do each day. Getting to try some hands-on activities for those jobs sounds like it could be really fun too!I remember a couple years ago, we had people from the community come in for Career Day and talk about their jobs. It was interesting listening to them explain what their workday is like and some of the cool things theyget to do. But a whole class dedicated to learning about that seems way more exciting than just a one-day event. We'll really get to dive deep and understand what various occupations involve.One thing I'm curious about is if we'll get to go on any field trips for Labor Class. How awesome would it be to actually visit places like firehouses, TV stations, restaurants, and see those workers in action? I bet it would make learning about the jobs a lot more interesting than just reading about them from a book. Getting to be hands-on seems like it will make the class a lot more engaging.From what Mrs. Roberts described, it sounds like Labor Class will have a big focus on developing important skills too. Things like teamwork, problem-solving, communication, and being responsible and organized. Those are abilities that are probably good to start learning about and practicing while we're young. That way we can continue developing them as we get older and eventually join the workforce someday ourselves.I can understand why the school wants to teach us these kinds of skills too. My parents are always stressing how important it is to be a good team player and work well with others. Whenever I've had group projects at school, there always seems to be someone who struggles to cooperate and do their fair share of the work. Learning about how to be a productive part of a team could be really helpful.Problem-solving skills are something that seem like they'd be super useful in any career too. My dad often talks about having to think critically and come up with solutions to issues that come up at his job. He says a big part of his role is analyzing problems and finding the best way to resolve them. Having hands-on projects in Labor Class where we get to work through challenges and figure out how to handle them could give us great practice for this.Communication is probably a skill that everybody uses constantly at work too. Whether it's giving presentations, sending emails, talking on the phone, or just chatting with coworkers and bosses. Being able to clearly share information and ideas seems really important. I know I could use some work on my communication abilities sometimes, so focusing on that in Labor Class would be helpful.Then there's being responsible and organized, which are qualities I imagine all employers appreciate. We've learned a bit about this through doing class jobs like being the line leader or classroom messenger. But going more in-depth on understanding why those traits are so vital could make us better prepared to be professionals ourselves someday.Overall, I'm really excited about the prospect of Labor Class!I think it's a great idea to start exposing kids like me to different career possibilities from an early age. That way we can begin exploring our interests and figuring out what future paths might be a good fit for us. The skills we'll develop related to teamwork, problem-solving, communication, and responsibility will be useful too, no matter what occupations we eventually pursue.I can't wait to get some hands-on experience learning about various jobs and doing projects related to them. It's going tomake learning a lot more fun and engaging than just reading from textbooks all the time. And who knows, Labor Class might even help some of us start discovering our calling and true passions! I'm really looking forward to this new class.篇4My Opinion on Having a Labor ClassHi there! My name is Tommy and I'm a 4th grader at Oakwood Elementary. Our principal, Mr. Johnson, recently told us that starting next year there will be a new required class called "Labor Class." When I first heard about it, I wasn't sure what to think. A class all about labor and work? That doesn't sound very fun! But after hearing more about it, I've decided I'm actually really excited for Labor Class. Let me tell you why.First of all, in Labor Class we're going to learn all kinds of useful skills for life. Things like woodworking, gardening, cooking, sewing, and even car maintenance! Those are skills that everyone needs to know how to do, but a lot of kids (including me) don't get taught them at home. My dad can't even change a tire or use a hammer without breaking his thumb. With Labor Class, we'll get hands-on experience with tools and materials so we can be prepared for the real world.I think it's really important to learn skills like that at a young age. It will make us more self-sufficient and capable of taking care of ourselves as we get older. Just imagine - I could build myself a sweet tree house or grow my own vegetable garden! Or if I ever locked my keys in the car, instead of having to call someone for help, I might be able to get the door open myself after taking Labor Class. How cool would that be?Another reason I'm looking forward to Labor Class is that it will get us moving around and working with our hands instead of just sitting at desks all day. Don't get me wrong, I love things like math, reading, and science too. But after a few hours of那until practice and worksheets, I start to get restless. My body wants to run around and create things! With woodworking, gardening, and the other labor skills, I'll get to be physically active and make real objects that I can use or even give as gifts. It's way more fun than just reading from a textbook.I also think Labor Class will prepare us for future jobs and careers. While some of my friends want to be video game designers or YouTube stars, I'm interested in more hands-on work like construction, mechanics, or landscaping. Learning the basics of tools, materials, and hard work in Labor Class will give me (and others like me) a head start toward those types ofcareers. Even for careers in offices, it will teach discipline and the value of a hard day's work.Plus, just imagine how helpful we'll be at home after taking Labor Class! No more asking our parents for everything. We could do repairs, cook meals, sew up torn clothes, and take care of outdoor chores ourselves. Our parents will be so impressed and proud of our new skills. We'll finally be contributing something, instead of just being couch potatoes.However, I can understand if some kids aren't too thrilled about having to take a Labor Class. It does mean more schoolwork, responsibility, and time spent on difficult hands-on projects instead ofly playing video games or watching TV. Some of my friends are worried it will be too much work on top of all our other classes and extracurricular activities. I get that - adding one more required class to an already busy schedule isn't ideal.But in my opinion, the benefits of Labor Class outweigh those concerns. It will teach us invaluable real-world skills, get us active, prepare us for future jobs, and make us into more capable, well-rounded individuals. We're still kids, but Labor Class will help us start taking first steps toward becoming responsible, hard-working adults. That's a good thing in my book!So while morning wood shop or gardening class might not sound as fun as recess, I'm going to go into Labor Class with an open mind and positive attitude. Learning has always been one of my favorite things, and I'm excited to learn skills that I'll actually use for the rest of my life. Bring it on! With some hard work and determination, I'll be the ultimate do-it-yourselfer by the time I graduate. Who knows, maybe I'll even take over some chores and projects from my parents! That would be a nice way to say thanks for giving me an awesome childhood. Labor Class, here I come!篇5My Views on Having Labor Lessons at SchoolHi there! My name is Tommy and I'm 10 years old. I go to Oakwood Elementary School. My teacher, Mrs. Roberts, asked us to write an essay about having labor lessons at school. Let me tell you all about my thoughts on this!First of all, what even are labor lessons? Well, from what I understand, they are classes where we would learn skills like cooking, cleaning, gardening, basic repairs and maintenance. Basically, stuff that helps you run a household and take care of yourself. I think it's a really good idea to have these at school.Why? Because these are super important life skills that everyone needs to know! I can't rely on my mom and dad to do everything for me forever. Plus, I want to be an independent grown-up one day. Knowing how to cook nutritious meals, do laundry, change a light bulb and things like that will really help me out.At the moment, my parents try to involve me in chores and get me to help out around the house sometimes. But a labor lesson would teach me the proper ways to do tasks. I could learn the correct techniques for mopping floors or washing windows to get them really clean and streak-free. The teachers could show me recipes and cooking methods to prepare yummy, healthy food.I think gardening would be my favorite labor lesson! How cool would it be to grow your own fruits and veggies? We could have a little garden area at school where each student gets their own patch to plant stuff. I would love getting my hands dirty and watching my plants grow from tiny seeds into big juicy tomatoes or crisp green beans. Plus gardening is good exercise from all that digging, watering and weeding.Sewing and woodworking could also be part of labor lessons. I'd enjoy making cute crafts and small wooden objects that Icould actually use or give as gifts. It allows you to create something unique with your own hands instead of just buying stuff from stores. My mom says sewing helps build patience and attention to detail, which are good qualities to have.Another reason labor lessons are a fantastic idea? They teach you crucial skills for the future! Maybe someday I'll be living on my own, or be a dad myself with a family to look after. Knowing how to cook, clean, make minor home repairs and grow my own food will come in so handy. I'll be totally prepared instead of having to rely on other people or spend tons of money on services.These skills could also help me earn money down the road. If I'm a whiz at baking, gardening or woodworking, I could potentially start a little business selling my goods and services. How awesome would that be to have a job doing something you really enjoy? Labor lessons give you options.Plus, doing hands-on tasks like those involved in labor lessons is just plain fun! It's a nice break from sitting at desks and doing paperwork or assignments all day. You get to move around and work with your hands to create things. It avoids boredom and gives your brain a different kind of exercise.I also think having labor lessons fosters good values like self-reliance, hard work and responsibility. If you're in charge of caring for a garden patch, you'll need to be diligent about watering and weeding it regularly. If you slack off, your plants will die. Knowing how to fend for yourself and get things done builds discipline. You learn that actions have consequences instead of just having everything handed to you.Of course, I'm sure some kids might not like labor lessons that much. They'll probably complain "This is too much work!" or "Why do I need to learn this stuff?" But those are the kind of whiny attitudes that won't get you far in life. The world doesn't owe you anything – you need to be able pull your own weight.My friend Kevin thinks labor lessons would be "embarrassing" because "cooking, cleaning and sewing are just for girls." That's a pretty silly and immature view if you ask me. There's nothing embarrassing about being a capable,well-rounded person who can take care of themselves! In my opinion, a real man should know his way around a kitchen, tool shed and laundry room.Some parents might not like labor lessons either because they think kids should just focus on "academic" subjects like math, science, reading and so on. But I say why not balance booklearning with some real-world practical skills? Working with your hands and learning to be self-sufficient is just as important in my books.In my ideal version of labor lessons, we'd have classes every couple of days where we rotate through stations learning different skills. One day could be cooking, next is gardening, then after that is woodworking and so on. We'd learn how to follow instructions, work safely with tools and cleanup afterwards. Maybe we could even get homework assignments to practice our new skills!Overall, I'm totally in favor of having labor lessons as a required part of the school curriculum. The skills you gain are just too valuable not to learn. It fosters independence, responsibility and capability – all qualities that will serve me really well in the future. I'll feel so much more confident going out into the world knowing I can fend for myself instead of being clueless about basic life tasks. I'm all for anything that makes me a well-rounded, self-reliant person. Bring on those labor lessons – I'm ready!。

MathPlayer: Web-based Math AccessibilityNeil SoifferDesign Science, Inc140 Pine Avenue, 4th Floor.Long Beach, CA 90802 USA+1 562-432-2920neils@ABSTRACTMathPlayer is a plug-in to Microsoft’s Internet Explorer (IE) that renders MathML[11] visually. It also contains a number of features that make mathematical expressions accessible to people with print-disabilities. MathPlayer integrates with many screen readers including JAWS and Window-Eyes. MathPlayer also works with a number of TextHELP!’s learning disabilities products.Categories and Subject DescriptorsH.5.4 [Information Systems]: Information Interfaces and Presentation—User Issues.General TermsDesign, Human Factors.KeywordsPrint Disabilities, Visual Impairments, Math Accessibility, Assistive Technology, MathML1. INTRODUCTIONAccess to mathematical content by those with print-related disabilities (blindness, low-vision, and certain learning disabilities such as dyslexia) is limited. A number of projects have focused on math accessibility.Early work includes MathTalk[12], MAVIS[3], AsTeR[10], and TRIANGLE[2]. MathTalk was envisioned as a standalone product as was MAVIS, although MAVIS’s Nemeth Code[8] braille translation was integrated with Scientific Notebook[5]. AsTeR is built on top of EMACS and reads LaTeX documents. TRIANGLE use a notation that is similar to TeX, but with special characters replacing TeX’s math commands.More recent work has involved MathML. MathML is the World Wide Web Consortium’s (W3C) recommendation for including math in XML and most mathematical software supports importing and/or exporting MathML. MathML not only enables visual display of mathematical expressions, it can be used for computation or translated into speech or into one of the many math braille codes. Two larger projects that involve MathML are UMA[4] and Lambda[9]. Both projects have a strong focus on two-way translation between MathML and multiple braille math codes. They also include some standalone software for voicing and navigating math.Our work differs from previous work mainly in its focus – MathPlayer is a mainstream application that is also designed to work with popular assistive technology (AT) software. Our goal is to allow people to continue to use tools that they are already familiar with such as JAWS and IE, and not require them to use a different browser simply because the document they are reading contains mathematical expressions.2. MATHPLAYER FEATURESMathPlayer is a free plug-in for IE that displays MathML in Web pages. Because MathML is not an image format, MathPlayer is able to dynamically display a mathematical expression that matches the document’s font properties such as size and color. Hence, if a user chooses to read a document using a larger font size than standard or chooses a particular color scheme, the math will also be displayed using that larger font size or color scheme. Mathematical typography uses multiple font sizes. For example, subscripts and superscripts are typically reduced in size. Because of this, some parts of an expression may not be easily readable even though MathPlayer uses a font size that matches the rest of the (easily readable) document. Rather than requiring a user to enlarge the entire document, the user can click on an expression to obtain a magnified view of that single expression. This isshown below:MathPlayer supports speech generation and seamlessly works with many AT software products such as JAWS, Window-Eyes, and Read&Write 7. The MathPlayer interface for speech currently being used by most AT software restricts communication to simple text strings – no speech engine control strings can be used for prosody. However, two differing amounts of pauses are achieved by the judicious use of commas and periods. MathPlayer’s speech interface supports SAPI4[6], SAPI5[7], and SSML[1] tagged strings and we are working with AT vendors to make use of those interfaces.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.ASSETS3905, October 94512, 2005, Baltimore, Maryland, USAACM 1-59593-159-7/05/0010.MathPlayer supports several forms of navigation, although AT vendors currently do not make use of them. At the moment, because screen readers use an off-screen model, users can only navigate through the spoken verbal description of the math; no structural navigation is possible. We are working with several vendors to determine the best interface for their needs so that MathPlayer’s other modes of navigation are available to users.Synchronized highlighting of text with speech is a feature of many high-end screen magnifiers and learning disability tools. It seems very likely that synchronized highlighting of math and speech is useful and so this feature was added to MathPlayer. TextHELP’s BrowseAloud incorporates MathPlayer’s synchronized highlighting. MathPlayer’s synchronized highlighting is very flexible. The foreground and background colors can be changed, as can the granularity of synchronizationas is shown below:Finally, MathPlayer allows users to copy a MathML expressionso that it can be pasted into any MathML-aware program. This isparticularly useful for computation, but might also be useful whenused in conjunction with other software aimed at making mathaccessible.MathPlayer 2.0, which includes integrated speech with AT software, was released in the spring of 2004. It is available for free download from . 3. FUTURE WORKMathPlayer’s speech rules are currently built-in. We plan to letthem be customized so that alternate speech rules and rules forforeign languages can be used. The work is complicated by a needto support synchronized highlighting with the speech and the needto allow specification of prosodic information as part of the rules.Braille translation is not currently a part of MathPlayer. We planto define an API so that we can call third-party translators when adocument is being sent to an embosser.MathPlayer currently works only in Internet Explorer. Two other common formats for distributing documents are Microsoft Word and PDF. We are investigating methods to make mathematical expressions in those formats accessible also. For Word and other Microsoft Office products, this can be done by making use of MathType’s ability to translate most math expressions used in Word into MathML. Once in MathML, we can leverage the work done for MathPlayer in IE to speak, synchronize, and navigate the expression. For PDF, we are working with AIIM’s effort to define a Universal Access PDF document format standard (PDF/UA) that includes math. MathML will be embedded in a PDF document so that an Adobe Reader plug-in can access the MathML corresponding to a math expression and speak it, navigate it, and highlight it.4. ACKNOWLEDGMENTSWork on MathPlayer was supported in part by a SBIR grant from the National Science Foundation.5. REFERENCES [1] Burnett, D.C., Walker, M.R. and Hunt, A. Speech Synthesis Markup Language (SSML) Version 1.0, 2004, /TR/speech-synthesis/.[2] Gardner, J., Stewart, R., Francioni, J. and Smith, A., TIGER, AGC, AND WIN-TRIANGLE, REMOVING THE BARRIER TO SEM EDUCATION. in CSUN International Conference on Technology and Persons with Disabilities , (Los Angeles, CA, 2002).[3] Karshmer, A.I., Gupta, G., Geiiger, S. and Weaver, C.Reading and writing mathematics: the MAVIS project inProceedings of the third international ACM conference on Assistive technologies ACM Press, Marina del Rey,California, United States 1998 136-143[4] Karshmer, A.I., Gupta, G., Pontelli, E., Miesenberger, K., Ammalai, N., Gopal, D., Batusic, M., Stöger, B., Palmer, B. and Guo, H.-F. UMA: a system for universal mathematics accessibility. in Proceedings of the ACM SIGACCESSconference on Computers and accessibility , ACM Press, Atlanta, GA, USA, 2004, 55-62. [5] MacKichan Software. Scientific Notebook, .[6] Microsoft. Speech API 4.0 SDK Documentation, /speech/download/old/sdk40a.asp . [7] Microsoft. Speech API 5.1 SDK Documentation, /speech/download/sdk51/. [8] Nemeth, A. The Nemeth Braille Code for Mathematics and Science Notation . American Printing House for the Blind, Frankfort, 1972.[9] Nicotra, G. and others. Lambda Project, .[10] Raman, T.V. Audio System for Technical Readings . CornellUniversity, 1994. [11] Ron Ausbrooks, S.B., David Carlisle, Stéphane Dalmas, Stan Devitt, Angel Diaz, Max Froumentin, Roger Hunter, Patrick Ion, Michael Kohlhase, Robert Miner, Nico Poppelier, Bruce Smith, Neil Soiffer, Robert Sutor, Stephen Watt. Mathematical Markup Language (MathML) Version 2.0 (Second Edition), 2003, /TR/2003/REC-MathML2-20031021/. [12] Stevens, R.D., Edwards, A.D.N. and Harling, P.A. Access to mathematics for visually disabled students through multi-modal interaction. Human-Computer Interaction (Special issue on Multimodal Interfaces). 47-92.。