限时练习三

高一基本不等式限时训练练习题第I卷（选择题）一、单选题（本大题共6小题，共30.0分）1.下列不等式一定成立的是()A. x+1x ≥2 B. x2+2√x2+2≥√2 C. x2+3√x2+4≥2 D. 2−3x−4x≥22.已知x>2，函数y=4x−2+x的最小值是()A. 5B. 4C. 6D. 83.已知t>0，则y=t2−4t+1t的最小值为()A. −2B. 12C. 1D. 24.若a，b都为正实数，2a+b=1，则ab的最大值是()A. 29B. 18C. 14D. 125.已知不等式2x+m+2x−1>0对一切恒成立，则实数m的取值范围是()A. m>−6B. m<−6C. m>−8D. m<−86.已知实数a，b满足ab=1，则a2+b2的最小值为()A. 4B. 3C. 2D. 1二、多选题（本大题共1小题，共5.0分）7.下列说法中正确的有()A. 不等式a+b≥2√ab恒成立B. 存在a，使得不等式a+1a≤2成立C. 若a，b∈(0,+∞)，则ab +ba≥2D. 若正实数x，y满足x+2y=1，则2x +1y≥8第II卷（非选择题）三、单空题（本大题共4小题，共20.0分）8.若正数a，b满足a+b=1，则9a +1b的最小值为．9.若正实数x，y满足y(x−y)=1，则2x+y的最小值为．10.已知正实数x，y满足xy+2x+y=3，那么xy的最大值为______．11.函数的最小值是__________．四、解答题（本大题共4小题，共48.0分）12.如图，某人计划用篱笆围成一个一边靠墙(墙的长度没有限制)的矩形菜园.设菜园的长为xm，宽为ym．(1)若菜园面积为，则x，y为何值时，可使所用篱笆总长最小;(2)若使用的篱笆总长度为30m，求1x +2y的最小值．13.已知ab−4a−b−5=0(a>1)(1)求ab的最小值；(2)求a+b的最小值．14. (1)已知正数a,b 满足1a +2b =1，求ab 的最小值；(2)已知x >1，求函数f(x)=x +1x−1的最小值．15. (1)已知x <54，求函数y =4x −1+14x−5的最大值．(2)已知0<x <12，求y =12x(1−2x)的最大值．答案和解析1.【答案】B【解析】【分析】本题主要考查不等式求解范围，属于基础题．根据不等式求最值和特殊值法求解即可．【解答】解：A项中当x<0时，x+1x<0<2，∴A错误;B项中，2√x2+2=√x2+2≥√2，∴B正确;而对于C，当x=0时，2√x2+4=32<2，显然选项C不正确;D项中，取x=1，则2−3x−4x=−5<2，∴D错误．故选B．2.【答案】C【解析】【分析】本题考查利用基本不等式求最值，属于基础题．由于y=4x−2+x=4x−2+(x−2)+2，且x−2>0，利用基本不等式即可求解．【解答】解：y=4x−2+x，因为x>2,故x−2>0，所以根据基本不等式可知：y=4x−2+(x−2)+2≥2√4x−2×(x−2)+2=6，当且仅当4x−2=x−2即x=4时取“=”．故选C．3.【答案】A【解析】【分析】本题主要考查利用基本不等式求最值，属于基础题．对原式进行化简，利用基本不等式求最值即可，注意等号取得的条件．【解答】解：t>0，则y=t2−4t+1t =t+1t−4≥2√t·1t−4=−2，当且仅当t=1t，即t=1时，等号成立，则y=t2−4t+1t的最小值为−2．故选A．4.【答案】B【解析】【分析】本题主要考查了利用基本不等式求解最值，属于基础题．由已知结合基本不等式可得ab=12(2a⋅b)≤12(2a+b2)2，可得结果．【解答】解：因为a，b都为正实数，2a+b=1，则ab=12(2a⋅b)≤12(2a+b2)2=12×14=18，当且仅当2a=b=12时取等号．故选：B．5.【答案】A【解析】 【分析】本题考查了基本不等式，不等式恒成立问题，考查了计算能力，属于中档题． 不等式2x +m +2x−1>0可化为2(x −1)+2x−1>−m −2，将不等式恒成立问题转化为最值问题，再利用基本不等式进行求解即可． 【解答】解：不等式2x +m +2x−1>0可化为2(x −1)+2x−1>−m −2， ∵x >1，∴x −1>0， ∴2(x −1)+2x−1≥2×√2(x −1)⋅2x−1=4，当且仅当x =2时取等号，∵不等式2x +m +2x−1>0对一切x ∈(1,+∞)恒成立， ∴−m −2<4， 解得m >−6， 故选A ．6.【答案】C【解析】 【分析】本题主要考查了基本不等式的应用，属基础题． 由重要不等式a 2+b 2≥2ab 即可求解． 【解答】解：由重要不等式可得：a 2+b 2≥2ab =2，当且仅当{ab =1a =b 即{a =1b =1或{a =−1b =−1时等号成立，所以a 2+b 2的最小值为2， 故选：C ．7.【答案】BCD【解析】【分析】本题考查基本不等式，属于中档题．结合基本不等式的一正，二定，三相等的条件检验各选项即可判断．【解答】解：选项A:不等式a+b⩾2√ab恒成立的条件是a≥0，b≥0，故A不正确；选项B:当a为负数时，不等式a+1a⩽2成立，故B正确；选项C:若a，b∈(0,+∞)，由基本不等式可知ba +ab⩾2√ba·ab=2，当且仅当a=b时，等号成立，故C正确；选项D:对于2x +1y=(2x+1y)(x+2y)=4+4yx+xy≥4+2√4yx·xy=8，当且仅当x=12,y=14时取等号，故D正确．故选BCD．8.【答案】16【解析】【分析】本题主要考查基本不等式的应用，属于基础题．可对式子9a +1b乘以1，也即乘以a+b，再使用基本不等式即可求出答案．【解答】解：∵正数a，b满足a+b=1，∴9a +1b=(9a+1b)(a+b)=9+ab+9ba+1=10+ab+9ba≥10+2√ab⋅9ba=16，当且仅当{ab=9baa+b=1，也即当{a=34b=14时取“=”．故答案为：16．9.【答案】2√6【解析】【分析】本题考查利用基本不等式求最值，属中档题．先由y(x−y)=1化简得x=1y+y，再利用基本不等式求出答案．【解答】解：由正实数x，y满足y(x−y)=1得xy=1+y2，即x=1y+y，所以2x+y=2y+3y⩾2√6，当且仅当2y=3y，即y=√6时，等号成立，3则2x+y的最小值为2√6．故答案为2√6．10.【答案】7−2√10【解析】【分析】由题意和基本不等式可得3≥xy+2√2xy，解不等式即可求出．本题考查基本不等式，涉及一元二次不等式的解集，属基础题．【解答】解：∵xy+2x+y=3，∴3≥xy+2√2xy，整理可得(√xy+√2)2≤5，解得√xy≤√5−√2，∴xy≤7−2√10当且仅当2x=y即x=−2+√10且y=−2+√10时取等号，2∴xy的最大值为7−2√10，故答为：7−2√10．11.【答案】2√6【解析】【分析】本题考查基本不等式的应用，考查学生的计算能力，属于一般题． 由 x >1，所以 x −1>0，化简 f (x )=2x 2−4x+5x−1=2(x−1)2+3x−1=2(x −1)+3x−1，利用基本不等式求最小值． 【解答】解：因为x >1，所以x −1>0， f (x )=2x 2−4x+5x−1=2(x−1)2+3x−1=2(x −1)+3x−1，2(x −1)+3x−1≥2√2(x −1)⋅3x−1=2√6， 当且仅当 2(x −1)=3x−1，即 x =1+√62， f(x)有最小值 2√6，故答案为2√6．12.【答案】解：(1)由已知可得xy =72，篱笆总长为(x +2y)m ．又因为x +2y ≥2√2xy =24，当且仅当x =2y ，即x =12，y =6时等号成立． 所以当x =12，y =6时，可使所用篱笆总长最小． (2)由已知得x +2y =30， 又因为(1x +2y )(x +2y)=5+2y x+2x y≥5+2√2y x ⋅2x y=9，所以1x +2y ≥310，当且仅当x =y ，即x =10，y =10时等号成立． 所以1x +2y 的最小值是310．【解析】本题考查基本不等式的实际应用和利用基本不等式求最值． (1)由已知可得xy =72，篱笆总长为(x +2y)m ，结合基本不等式即可得解； (2)由已知得x +2y =30，又因为(1x +2y )(x +2y)=5+2y x+2x y，利用基本不等式即可求解．13.【答案】解：(1)∵ab −4a −b −5=0(a >1)∴b =4a +5a −1(a >1) ∴a ⋅b =a ⋅4a+5a−1=4a 2+5a a−1(a >1)，令a −1=t(t >0)，则a =t +1∴a ⋅b =4(t +1)2+5(t +1)t (t >0)a ⋅b =4t 2+13t +9t(t >0)a ⋅b =4t +9t +13(t >0)，∵t >0，∴4t +9t ≥2√4t ⋅9t =12，当且仅当4t =9t ，即t =32时取“=”，∴ab ≥25，当且仅当{a =52b =10时取“=”， 即当{a =52b =10时，ab 有最小值25；(2)∵a +b =a +4a+5a−1(a >1)，令a −1=t(t >0)，则a =t +1， ∴a +b =t +1+4(t+1)+5t(t >0)，∴a +b =t +9t+5(t >0)， ∵t >0，∴t +9t ≥2√t ⋅9t =6，当且仅当t =9t ，即t =3取“=”．∴a +b ≥11，当且仅当{a =4b =7时取“=”，即当{a =4b =7时，a +b 有最小值11．【解析】本题考查基本不等式的应用，考查利用基本不等式求最值，属于基础题．(1)由已知可得b=4a+5a−1(a>1)，即可得到a⋅b=4a2+5aa−1(a>1)，令a−1=t(t>0)，可得a⋅b=4t+9t+13(t>0)，利用基本不等式即可求解ab的最小值；(2)由已知可得a+b=a+4a+5a−1(a>1)，令a−1=t(t>0)，即可得到a+b=t+9t+5(t>0)，利用基本不等式即可求解a+b的最小值．14.【答案】(1)解：a>0,b>0，1 a +2b⩾2√2ab，又1a +2b=1，∴2√2ab⩽1，则√2ab ⩽12，∴2ab ⩽14，则ab⩾8，当且仅当a=2，b=4时等号成立，∴ab的最小值为8．(2)由题意，f(x)=x+1x−1=x−1+1x−1+1∵x>1，∴x−1>0，∴(x−1)+1(x−1)⩾2√(x−1)(1x−1)=2，当且仅当x=2时等号成立，∴f(x)⩾3，∴f(x)的最小值为3．【解析】本题主要考查了利用基本不等式求最值，属于基础题．(1)由题意1a +2b⩾2√2ab，又1a+2b=1，则√2ab⩽12，则ab⩾8，可得结果．(2)由题意，f(x)=x+1x−1=x−1+1x−1+1，利用基本不等式即可求最小值．15.【答案】解：(1)∵x<54，∴4x−5<0，5−4x>0.∴y=4x−1+14x−5=4x−5+14x−5+4=−[(5−4x)+15−4x]+4，第11页，共12页第12页，共12页 ∵5−4x +15−4x ⩾2√(5−4x )·15−4x =2，∴y ≤−2+4=2，当且仅当5−4x =15−4x 即x =1时取等号．∴y max =2．(2)∵0<x <12，∴1−2x >0，∴y =14×2x(1−2x)≤14×(2x +1−2x 2)2=14×14=116，当且仅当2x =1−2x (0<x <12)，即x =14时，上式等号成立，故当x =14时，y max =116．【解析】(1)由y =4x −5+14x−5+4=4−(5−4x +15−4x )，利用基本不等式可求；(2)由y =12x(1−2x)=14×2x(1−2x)，利用基本不等式可求；本题主要考查了利用基本不等式求解最值，要注意和为定值时，积有最大值，积为定值时，和有最小值的应用，属于基础试题．。

限时训练(三）正确使用标点符号1.下列句子中标点符号使用正确的一项是（）A．高考作文专家指出，近年的话题作文有利也有弊，它虽使应试作文减少了限制、增强了自主性，有利于学生发挥写作能力，但也给套题、抄袭开了方便之门。

B．处于争议漩涡中的跨行查询收费对储户的影响到底有多大，记者昨日从中国银联获得的数据显示，自6月1日开收0.3元跨行查询费用至今一个多月的时间，全国ATM的跨行查询量减少了10%左右。

C．长假过后，于丹授课的网络视频点击、下载量节节攀升，网友好评如潮，因“俗事”缠身而二十多天未写博客的易中天也为此“破例”开博，写道：“于丹真棒”！D．山西省省长于幼军在调查“黑砖窑”问题时发现，一些干部对非法用工、无证照经营、拐骗和强迫农民工劳动、使用智障人员和童工等危害群众切身利益、损害人格尊严的行为竟熟视无睹。

【答案】D【解析】Ａ项“限制”后的顿号应改为逗号，顿号用于并列的词或短语之间，但并列的谓语之间不能用顿号；Ｂ项“多大”后的逗号应改为问号，问号是表示疑问句结束的停顿；Ｃ项叹号应在引号里面，此处为完全引用。

2.下列各句中，标点符号使用正确的一句是（）A．对当代企业高级管理者来说，意识到这一点：计算机化企业、计算机化经济时代和计算机化企业经济管理思想正在形成，是极为重要的。

B．在八艺节筹备和举办期间，“鹿角立鹤”被广泛用于宣传、演出、展览等活动，使荆楚文化得到了充分的展现和宣传。

C．战国之时，“邦无定交，士无定主”（顾炎武《日知录·周末风俗》），一般游士，都肆无忌惮，说话比较随便。

D．伊能静《爱的练习本》预售已攻进排行榜。

文中充满了一段段爱情呓语，让人忍不住猜疑：这是对哈林说的？还是另有其人？【答案】C【解析】Ａ项冒号使用不恰当，可将冒号改为破折号；Ｂ项省略号与“等”不能同时使用，可删去省略号；Ｄ项选择问句，只在最后用问号，第一个问号应改为逗号。

3.下列句子中，标点符号使用不正确的一项是（）A．这首诗将两种相互对立的行为——“离别”与“相逢”、两种不同的情感——“伤心”与“庆幸”并列，表现了爱情的美好与纯真，引发了人们的强烈共鸣。

吴忠回中高三生物限时练习三一、 选择题：1．下表中a 、b 、c 符合如右图所示关系的是 （ ）2．下图表示细胞中两种重要的新陈代谢过程，有关叙述正确的是（ ）A ．乙过程只能发生在叶绿体中B ．甲过程发生在线粒体中C ．乙可以表示化能合成作用的部分过程D ．甲可以表示乳酸菌的细胞呼吸3．右图示某生物正在进行某种分裂的细胞，等位基因A 和a 位于染色体的位置（不考虑交叉互换）可能是（ ） A ．A 位于①上，a 位于⑤上 B ．A 位于⑤上，a 位于⑦上C ．该细胞只有a ，分别位于①和③上D ．该细胞只有A ，分别位于②和⑥上4、昆虫学者Alain Robichon 最近发现蚜虫体内的类胡萝卜素能吸收光能，并把它传送给负责能量生产的组织细胞。

阳光下，蚜虫的ATP 生成将会增加，黑暗时，其ATP 含量便会下降。

下列关于蚜虫产生ATP 的说法正确的是（ ） A ．ADP 合成ATP 时需要的能量只能来自光能 B ．黑暗中大量产生ATP 时一定伴随着O 2的消耗 C ．类胡萝卜素吸收光能发生在类囊体薄膜上 D ．相同情况下黄光照射比蓝紫光照射ATP 含量上升快5、哺乳动物红细胞的部分生命历程如下图所示，图中除成熟红细胞外，其余细胞中均有核基因转录的RNA ，下列叙述正确的是（）A. 造血干细胞与幼红细胞中基因的执行情况相同B. 成熟红细胞除进入凋亡历程外还可能发生癌变C. 网织红细胞仍然能够合成核基因编码的蛋白质D. 成熟红细胞衰老后控制其凋亡的基因开始表达 6、下列关于种群基因库的叙述，错误的是（ ） A ．一个种群所含的全部基因叫做这个种群的基因库B ．生物个体总是要死亡的，但基因库却因种群个体的繁殖而代代相传C ．种群中每个个体含有该种群基因库的全部基因D ．基因突变可改变种群基因库的组成 选择题答案：二、非选择题29．（10分）萌发的小麦种子中淀粉酶活性较强，主要有α—淀粉酶和β—淀粉酶。

α—淀粉酶不耐酸、较耐热，在pH 为3.6以下迅速失活，而β—淀粉酶不耐热，在70℃条件下15 min 后失活。

限时精练三45分钟综合性过关小练习(三)注意事项:1. 答题前,考生务必将学校、班级、姓名写在密封线内。

2. 请将选择题的答案根据老师批改需要填写在试卷第3页所附的答题栏内。

一、完形填空请认真阅读下面短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项。

Many language learners think their pronunciation is good enough because their teacher doesn’t correct them too often or because other students can 1 them.Pronunciation is the area which is 2 the least attention to in language learning. Most teachers 3 just let their students speak and stop them 4 they say something completely wrong. Working on each student’s pronunciation in class is just 5 . Also, the students who are 6 at pronunciation may be afraid that it will embarrass their classmates if they help 7 their mistakes.If you believe your pronunciation is good enough to 8 because it is good enough for your teacher and other students, you may be 9 when you actually go to a foreign country. One of my friends was the best student in his 10 class in Poland. When he went to America, he found Americans didn’t understand 11 of what he said.Your pronunciation may still be quite 12 that of a native speaker. If this is the 13 , other people will find it 14 to understand what you’re saying and will not be comfortable with you.15 , don’t think you can communicate in a foreign language 16 you’ve tested your skills on real native speakers. 17 for native or near-native pronunciation so that people you talk to can communicate with you 18 . In order toachieve this goal, there’s19 that you will need to start thinking about pronunciation and 20 time on it.( )1. A. mistake B. watch C. surround D. understand( )2. A. fixed B. drawn C. paid D. called( )3. A. never B. ever C. even D. usually( )4. A. only if B. if only C. even if D. if ever( )5. A. fantastic B. impossible C. necessary D. important( )6. A. poor B. well C. good D. strict( )7. A. find out B. work out C. try out D. point out( )8. A. communicate B. travel C. pronounce D. exchange( )9. A. happy B. disappointed C. surprised D. excited( )10. A. Polish B. French C. German D. English( )11. A. none B. half C. rest D. lot( )12. A. near to B. different from C. far from D. from far( )13. A. same B. matter C. case D. fact( )14. A. easy B. beneficial C. convenient D. hard( )15. A. In conclusion B. In a word C. On the contrary D. In short( )16. A. when B. until C. unless D. while( )17. A. Stand B. Look C. Aim D. Account( )18. A. smoothly B. difficultly C. truly D. practically( )19. A. no way B. no need C. no doubt D. no wonder( )20. A. take B. cost C. spend D. kill二、阅读理解请认真阅读下列短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项。

50分阅读限时满分练(三)(限时35分钟)Ⅰ.阅读理解(共15小题; 每小题2.5分, 满分37.5分)ASan Francisco Fire Engine ToursSan Francisco Winery TourRunning: February 1st through April 30thThis delicious tour goes through the city on its way to Treasure Island where we will stop at the famous Winery SF.Here you can enjoy 4 pours of some of the best wine San Francisco has tooffer.(Included in ticket price)Departing from the Cannery:Tour times upon requestDuration(时长): 2 hoursPrice: $90Back to the Fifties TourRunning: August 16th through August 31stThis tour transports you back in time to one of San Francisco’s most fantastic periods, the 1950s! Enjoy fun history as we take you through San Francisco for a free taste of ice cream.Departing from the Cannery: 5:00 p.m. and 7:30 p.m.Duration: 2 hoursPrice: $90Spooky Halloween TourRunning: October 10th through October 31stJoin us for a ride through the historical Presidio district.Authentic fire gear(服装) is provided for your warmth as our entertainers take you to some of the most thrilling parts of San Francisco.Departing from the Cannery: 6:30 p.m. and 8:30 p.m.Duration: 1 hour and 30 minutesPrice: Available upon requestHoliday Lights TourRunning: December 6th through December 23rdThis attractive tour takes you to some of San Francisco’s most cheerful holiday scenes. Authentic fire gear is provided for your warmth as you get into the holiday spirit.Departing from the Cannery: 7:00 p.m. and 9:00 p.m.Duration: 1 hour and 30 minutesAdvance reservations required.1.Which of the tours is available in March?A.San Francisco Winery Tour.B.Back to the Fifties Tour.C.Spooky Halloween Tour.D.Holiday Lights Tour.2.What can tourists do on Back to the Fifties Tour?A.Go to Treasure Island.B.Enjoy the holiday scenes.C.Have free ice cream.D.Visit the Presidio district.3.What are tourists required to do to go on Holiday Lights Tour?A.Take some drinks.B.Set off early in the morning.C.Wear warm clothes.D.Make reservations in advance.B(2021·陕西高三模拟)It was a dark night. Thick, dark, gray clouds had made sure that there was no starlight or moonlight to greet me as I walked out on my porch. Still, I kept the porch light off because I didn’t want to be surrounded by bugs and moths(飞蛾) on this sticky summer evening. I stood there for a while letting my eyes adjust to the lack of light. My dog stood beside me waiting patiently for me to start her walk. It was then, though, that I saw them. First one blink of light at the far end of the meadow was followed by another and then another. I smiled. I recognised them at once as my firefly friends, who always showed up at this time of year.I got so much joy watching them first as a child and then as an adult. They never became dull or boring and they always filled me with delight. When I was little I used to sit in the grass and watch them slowly fly around blinking on and off. I never caught and put one in a jar as some kids did because I was afraid I might kill it and I never wanted to hurt these messengers(信使) of light. Their time on earth was so brief as it was. I tried to enjoy them each time they were here. It always saddened me when they disappeared in the fall and it always made my heart sing when they reappeared the next summer.I think I enjoy these little fireflies so much because I can see that we are like them in a lot of ways. Our time here on earth is brief. Often our light and love are more like blinks rather than a steady shine. Let’s share our light and love while we are here then.4.Why did the author turn off his porch light?A.To avoid some insects.B.To adapt to surroundings.C.To search for his dog.D.To greet special friends.5.What can we know about fireflies?A.They always frightened the author.B.Most kids caught and killed them.C.The author watched them every night.D.They usually brightened the author.6.What does the author mainly convey through the story?A.Value our short life in the world.B.Protect fireflies as well as possible.C.Devote ourselves as much as possible.D.Share as many inspiring stories as possible.7.What can be the best title for the text?A.A Special Summer NightB.Messengers of LightC.Human’s Best FriendsD.Fireflies — Shinning ForeverC(2021·河北唐山二模)A 293-million-mile journey of the NASA Perseverance rover(探测器) to Mars ended successfully on February 18, 2021, with a picture-perfect landing inside the Jezero Crater. The car-sized, six-wheeled rover, nicknamed Percy is the US space agency’s biggest and most advanced explorer to date. Its primary mission is to search for signs of ancient microbial(微生物的) life on Mars.Landing on Mars is extremely tricky. The Red Planet’s gravitational pull causes the approaching spacecraft to go faster to high speeds, while its thin atmosphere—just 1 percent of the Earth’s—does little to help slow it down as it approaches the surface.The scientists had to reduce Percy’s 12,000 mph speed to a safe landing speed of less than five mph—in just six and a half minutes. The target entry angle also had to be precise 12 degrees—any steeper, and the spacecraft would burn up; any flatter, and it would get lost in space. It is no wonder that the final approach is often referred to as the “seven minutes of terror”.Upon attaining a manageable speed, Percy briefly flew over the Martian surface to seek out the perfect landing spot. Its complex map-reading system rapidly scanned the area and matched it with maps in its database to find the best location.The NASA scientists spent the next two months testing Percy’s scientific instruments. Once ready, the rover would begin to carry out its mission.“Perseverance is the smartest robot ever made but confirming that microbial life once existed carries an unusually large burden of proof,” said Lori Glaze, director of NASA’s Planetary ScienceDivision.“While we’ll learn a lot with the great instruments we have aboard the rover, it may very well require the far more well-equipped laboratories and delicate instruments back here on Earth to tell us whether our samples carry evidence that Mars once harboured life.”8.What is the extraordinary challenge for the rover to land on Mars?A.The speed reduction.B.The atmosphere analysis.C.The location search.D.The time management.9.What is paragraph 3 mainly about?A.Ways to find the precise entry angle.B.Consequences of a wrong entry degree.C.Factors to survive “the seven minutes”.D.Reasons for the necessity of speed reducing.10.What does “it” refer to in paragraph 4?A.The spot.B.The area.C.The system.D.The surface.11.What can be inferred from Lori Glaze’s words?A.Instruments aboard the rover are not quite reliable.B.Perseverance is able to collect enough evidence needed.C.Man still has a long way to go to prove life was on Mars.D.Samples of Mars will be returned soon to our labs on Earth.DI told my friend Graham that I often cycled two miles from my house to the town centre but unfortunately there was a big hill on the route. He replied,“You mean fortunately.” He explained that I should be glad of the extra exercise that the hill provided.My attitude to the hill has now changed. I used to complain as I approached it but now I tell myself the following. This hill will exercise my heart and lungs. It will help me to lose weight and get fit. It will mean that I live longer. This hill is my friend. Finally I comfort myself with the thought of all those silly people who pay money to go to a gym and sit on stationary exercise bicycles when I can get the same value for free. I have a smile of satisfaction as I reach the top of the hill.Problems are there to be faced and overcome. We cannot achieve anything with an easy life. Helen Keller was the first deaf and blind person to gain a university degree. Her activism and writing proved inspirational. She wrote,“The character cannot be developed with ease. Only through experiences of suffering can the soul be strengthened, vision cleared, ambition inspired and success achieved.”One of the main determinants of success in life is our attitude towards adversity. From time to time we all face hardships, problems, accidents and difficulties. Some are of our own making but many confront us through no fault of our own. While we cannot choose adversity, we can choose our attitude towards it.Douglas Bader was 21 when in 1931 he had both legs cut off following a flying accident. He was determined to fly again and went on to become one of the leading flying aviators in the Battle of Britain with 22 aerial victories over the Germans. He was an inspiration to others during the war. He said,“Don’t listen to anyone who tells you that you can’t do this or that. That’s nonsense. Make up your mind, andyou’ll never use crutches or a stick, and then have a go at everything. Go to school, and join in all the games you can. Go anywhere you want to. But never, never let them persuade you that things are too difficult or impossible.”The biographies of great people are full of examples of how they took steps to overcome the difficulties they faced. The common thread is that they did not become depressed. They chose their attitude. They chose to be positive. They took on the challenge. They won. Nevertheless, there is still the problem of how you change your attitude towards adversity.12.Which of the following is true according to the author of the passage?A.Those who want to achieve success can’t expect to live an easy life.B.Climbing hills on bicycles is the best way to take exercise.C.Going to a gym is greatly beneficial to people’s health.D.People’s attitude towards hardships is the only factor of their success.13.By quoting what Douglas Bader said, the author intends to tell us “” .A.Failure is the mother of successB.A bad workman quarrels with his toolsC.Nothing is difficult to the man who will tryD.If you risk nothing, you will have nothing14.Following this passage, the author will further talk about .A.how his friend helped him to change his attitude towards the challenge he facedB.why it is important to keep optimistic in the face of troubleC.what steps to take to change your attitude towards the difficulties you faceD.what great people have in common15.Which of the following can be the best title of the passage?A.Different attitudes towards misfortuneB.Face difficulties with a smileC.Nothing is impossibleD.Life is full of adversityⅡ.七选五(共5小题; 每小题2.5分, 满分12.5分)(2021·安徽安庆高三二模)How to Make a Classroom Management PlanStudents need to feel comfortable and safe in order to learn effectively. As an educator, you need to manage your classroom in such a way that you create this sort of environment. A classroom management plan is a strategy you create and carry out. 16 It can help you deal with negative behaviours as well.17 Many classroom management plans begin with the teacher’s philosophy of motivation. Basically, it lays out what you believe about education and how students should learn. You can talk about the environment you want to create and how you plan to create that environment, both physically and emotionally.Set the tone on the first day of class. Start building relationships with your students by being friendly and getting to know each other. 18 So they know in advance how you expect them to behave.19 Get your students’ parents on board by laying out your basic rules. You can also tell them about the systems of rewards and consequences. That way, parents know what to expect throughout the year.Set the example.20 For instance, show you are respectful of each student’s ideas. It will let them know they can trust you.Be consistent. Probably the most important part of any classroom management plan is being consistent with how you carry it out. That means enforcing(执行) rules even when you don’t want to, as kids will come to understand that you mean what you say in the classroom.A.Determine your philosophy.B.Understand each child’s motivation.C.Create a formal letter for consequences.D.Write a letter about the plan to send home.E.Share the rules, rewards, and consequences.F.It is important that you follow the classroom rules, too.G.It can help you get and maintain control of the classroom.50分阅读限时满分练(三)【语篇导读】本文是一篇应用文。

高三数学题限时练习题第一题：已知函数f(f)=ff^2+ff+f，其中f，f，f为常数，且f≠0。

已知当f=2时，f(f)=3；当f=1时，f(f)=1。

请回答以下问题：1. 根据已知条件，列出函数f(f)的方程式。

2. 求函数f(f)的导函数f′(f)。

3. 若函数f(f)的极值点为f=−1，求函数f(f)在f=−1处的极值。

解答：1. 假设函数f(f)的方程式为f(f)=ff^2+ff+f。

由已知条件可以得到如下方程组：3 = 4f+2f+f (1)1 = f+f+f (2)解方程组 (1) 和 (2)，可以得到f=1，f=-1，f=3。

因此，函数f(f)的方程式为f(f)=f^2−f+3。

2. 函数f(f)的导函数f′(f)可以通过求函数f(f)的变化率来得到。

根据导数的定义，有：f′(f) = lim(f→0) (f(f+f)−f(f))/f对函数f(f)=f^2−f+3进行求导，得到：f′(f) = 2f−1所以，函数f(f)的导函数f′(f)为2f−1。

3. 函数f(f)的极值点为f=−1，可以通过求导数为0的点来求得。

令f′(f)=0，有：2f−1 = 0解方程得到f = 1/2。

即函数f(f)在f=−1处的极值为f=1/2。

第二题：已知函数f(f)=f^3+ff^2+ff+f，其中f，f，f为常数。

请回答以下问题：1. 当f=2时，f(f)=1；当f=1时，f′(f)=2。

根据已知条件，列出函数f(f)的方程式以及函数f(f)的导函数f′(f)的方程式。

2. 求函数f(f)的导函数f′(f)的导函数f′′(f)。

3. 若函数f(f)的极值点为f=−1，求函数f(f)在f=−1处的极值。

解答：1. 假设函数f(f)的方程式为f(f)=f^3+ff^2+ff+f。

根据已知条件可以得到如下方程组：1=8+4f+2f+f (1)2=3+2f+f (2)解方程组 (1) 和 (2)，可以得到f=-2，f=3，f=-4。

限时训练刷题练习册一、选择题1. 下列哪个选项是正确的数学表达式？A. 2 + 3 = 5B. 3 × 4 = 12C. 4 ÷ 2 = 6D. 5 - 1 = 3答案：A2. 请从下列选项中选出正确的英语单词拼写。

A. colerB. colorC. collerD. cooler答案：B3. 以下哪个历史事件标志着第二次世界大战的结束？A. 珍珠港事件B. 诺曼底登陆C. 广岛原子弹爆炸D. 柏林墙倒塌答案：C二、填空题1. 地球的自转周期是 ________ 小时。

答案：242. 请填写下列化学元素的符号：铁 ________，氧 ________。

答案：Fe，O3. 根据题目要求，以下句子中缺少的单词是 ________。

- 句子：I am ________ to help you.答案：willing三、简答题1. 请简述牛顿第三定律的内容。

答案：牛顿第三定律指出，对于两个相互作用的物体，它们之间的作用力和反作用力大小相等，方向相反。

2. 请解释什么是光合作用，并简述其过程。

答案：光合作用是植物、藻类和某些细菌利用光能将水和二氧化碳转化为葡萄糖和氧气的过程。

这个过程主要发生在叶绿体中，分为光反应和暗反应两个阶段。

光反应产生ATP和NADPH，暗反应则利用这些能量和还原力将二氧化碳固定并转化为有机物。

四、计算题1. 如果一个圆的半径是5厘米，求这个圆的面积。

答案：圆的面积公式是A = πr²，代入 r = 5 厘米，得到 A = π × 5² = 25π ≈ 78.54 平方厘米。

2. 一个班级有40名学生，其中25名男生和15名女生。

如果随机选择一名学生，求选中男生的概率。

答案：选中男生的概率是男生人数除以总人数，即 P(男生) = 25/40 = 5/8。

结束语本练习册旨在帮助学生通过限时训练提高解题速度和准确率。

希望同学们能够认真完成每一道题目，不断提升自己的学习水平。

2015届高三理综化学限时练习之三第I 卷（共42分）相对原子质量:H:1 C:12 N:14 O:16 Mg:24 S:32 P:31 S:32 Fe:56 Cu:64 7．下列有关表示不正确的是8．下列有关化学实验的叙述中，不正确的．．．．是 A ．用饱和食盐水替代水跟电石作用，可以有效控制产生乙炔的速率B ．制肥皂时，在皂化液里加入饱和食盐水，能够促进高级脂肪酸钠的析出C ．制备乙酸乙酯时，为除去乙酸乙酯中的乙酸，用氢氧化钠溶液收集产物D ．重结晶法提纯苯甲酸时，为除去杂质和防止苯甲酸析出，应该趁热过滤 9．常温时，下列叙述正确的是A ．稀释pH=10的氨水，溶液中所有离子的浓度均降低B ．pH 均为5的HCl 和NH 4Cl 溶液中，水的电离程度相同C ．NaOH 和CH 3COONa 的混合溶液中，c (Na +)＋c (H +)═c (OH -)＋c (CH 3COO -)D ．分别中和pH 与体积均相同的硫酸和醋酸，硫酸消耗氢氧化钠的物质的量多 10．下列解释事实的化学方程式或离子方程式，不正确的．．．．是 A ．工业上可用电解法制备Mg ：MgCl 2 2↑B ．自然界中正常的雨水呈酸性：H 2O + CO 2H 2CO 3H + + HCO 3-C ．用CaSO 4治理盐碱地：CaSO 4(s) + Na 2CO 3(aq)CaCO 3(s) + Na 2SO 4(aq)D ．用FeSO 4除去酸性废水中的Cr 2O 72-：Cr 2O 72- + Fe 2+ + 14H + == 2Cr 3+ + Fe 3+ + 7H 2O 11．下列说法不正确．．．的是 A ．金属单质和盐溶液的反应都属于置换反应 B ．质量数相等的不同核素，一定属于不同种元素C ．室温下，等浓度的酸HA 盐酸的导电能力弱，所以HA 属于弱电解质D ．Al 2O 3既能与强酸反应，又能与强碱反应，所以Al 2O 3属于两性氧化物 12．下列各组物质混合后，加热、蒸干、灼烧至质量不变，最终能得到纯净物的是A ．向AlCl 3溶液中，加入一定量的NaOHB ．向NaI 和NaBr 混合溶液中，通入过量的Cl 2C ．向含1 mol NaHCO 3溶液中，加入1 mol Na 2O 2粉末D ．向含1 mol Na 2CO 3溶液中，加入含1 mol HCl 的盐酸 13．下图为某太空站的能量转化示意图，其中燃料电池用KOH 溶液为电解液。

每套30题，15分钟高考英语语法题15分钟限时模拟训练11. We had ___________ wonderful time_________the party_______ other day.A. a,on,theB./,at,onC. a,at,theD./,on,/2. It's said that __________ is going to give us a lecture.A. an American famous youngB. a famous American yougC. a famous young AmericanD. a young famous American3. Nearly________ of the surface of our planet is covered by water.A. seven-tenB. seven-tenthC. seven-tenthsD. seventh-ten4. You must have waited here for a long time ,___________you?A. mustn'tB. didn'tC. haven'tD. hadn't5. China has hundreds of islands, ___________ is Taiwan Island.A. among them the largestB. and the largest of whichC. and the largest of themD. but in which the largest6. --You don't look so well, Mary. What's the matter with you?--Why?___________.A. I'm quite myselfB. Fine, think youC. I felt badD. I'm not myself7. This new-type machine____________ little room.A. takes upB. is taken upC. has been taken upD. is taking up8. It is impossible for____________ little room.A. so, suchB. so, soC. such a, soD. such, such9. --You forgot your keys when you left home in the morning.--Good heavens,___________.A. so did I.B. so I did.C. so you did.D. so did you.10. __________ it rain, the crops_____________.A. Shall,would be savedB. Should, would be savedC. Would, should be safeD. Were, might be safe11. -Do you regret paying 500 dollars for your necklace?--No, I would gladly pay__________ for it.A. two times as muchB. twice as manyC. twice as muchD. as twice as much12.________ is quite natural,a beginner can't read the books written in English very quickly.A. WhichB. AsC. WhatD. It13. Take a taxi,___________ you'll miss your train.A. inB. duringC. throughoutD. within15. I coutdn't have got to the meeting on time____________ an earlier train.A. if I had not caughtB. unless I had caughC. if ! did not catchD. unless I caugh16. The black horse is___________ of the pair.A. the strongestB. the strongerC. the strongD. quite strong17. It is a rule in his family that __________ comes home earlier should cook the dinner for the family.A. anybodyB. whoC. who thatD. whoever18. I really wonder__________ he has posted me many parcels___________ we didn't work together.A how ,afterB why,when Cwhen,before D why,since19. --How long ___________ each other before they__________ married?--For about a year.A. have they known;getB. did they know; were going to getC. do they know;are going to getD. had they known; got20. Michael __________ here to see you and he____________ a note on your desk.A. has come; had leftB. has been; has leftC. has come; leftD. has been; left21. -When__________ and visit our exhibition next month?- When_______, I will let you know.A. will he come; he will comeB. will he come; he comesC. does he come; he will comeD. does he come; he comes22. What worried the child most was _________ to visit his mother in the hospital.A. his not allowingB. his not being allowedC. his being not allowedD.having not been allowed23. I__________ you somewhere before, but your name has escaped me_________.A. must see;for a momentB. must have seen; for a momentC. must see;for the momentD. must have seen; for the moment24. We're leaving at six o'clock ,and hope_________ most of the journey by lunch time.A. to doB. to have doneC. to makeD. to have made25. She was afraid __________ the dog in case it became dangerous.A. of excitingB. to exciteC. that she excitedD. to be exciting26．The bad weather meant__________ the rocket launch(发射)for 48 hours,．A.delaying B．having delayedC.to delay D．to have delayed27．D0 you consider it any good__________the truck again?A．to repair B．repairingC．repaired D．being repairing28．_____________to somebody，a British person often shakes hands with the stranger.A．Introducing B．To introduceC．To be int．roduced D．On being introduced29．__________ in thought，he almost ran into the car in front of him．A．Losing B．Having lost C．Lost D．To30．Mary ___________to see you．She．_________ for you downstairs at the moment．A．has come；is waiting B．came；is waitingC．has come；waited D．came；was waiting答案详解：1．C本题是冠词的考查。

班级：姓名：小组：第一节位置和疆域第二课时限时练习一、选择题：1.下列省(区)与简称、人民政府驻地的连线，正确的是（）Ａ.广西——粤——桂林 B.福建——闽——厦门C.青海——青——兰州D.贵州——黔——贵阳2、下列省区的简称和行政中心对应正确的是（）A、晋—石家庄B、鲁—郑州C、黔—贵阳D、滇—南宁3、下列是我国最早迎来日出的省区是：（）A、台B、黑C、新D、琼4、下列有关我国省级行政单位之最的叙述，错误的是（）A.纬度最低的省级行政单位是海南省B.跨经度最广的省级行政单位是内蒙古自治区C.面积最大的省级行政单位是新疆维吾尔自治区D.在一天中最后送走夕阳的省级行政单位是黑龙江5、同时濒临渤海和黄海的省级行政单位的简称是（）A.冀、鲁B.鲁、辽C.津、苏D.吉、辽6、我国纬度最高和最低的省区是（）A、黑和粤B、黑和琼C、新和台D、内蒙古和琼7、与西藏自治区相邻的国家有（）A、5个B、4个C、3个D、6个8、下列省区与省级行政中心的连线，正确的是（）A、江苏-----杭州B、安徽----南京C、江西-----福州D、河南----郑州9、下列我国行政区域划分，正确的是（）A、我国有23个省，5个自治区，4个直辖市，2个特别行政区；B、我国有22个省，5个自治区，3个直辖市，1个特别行政区；C、我国有23个省，5个自治区，4个直辖市，1个特别行政区；D、我国有24个省，5个自治区，4个直辖市，2个特别行政区。

10、下列省区具有两个简称的是（）A、黑龙江省B、海南省C、云南省D、广西壮族自治区11、北回归线自西向东依次穿过的省区是（）A、滇、桂、粤、台B、滇、桂、闽、台C、台、粤、桂、滇D、滇、粤、闽、台12、在少数民族自治区中，纬度最高的是（）A、桂B、内蒙古C、宁D、新13、我国第二大岛属于（）A、台湾省B、广东省C、海南省D、云南省14、在我国的省级行政区中，临海的有（）A、11个B、12个C、10个D、13个15、以下4个省区的简称分别是A、贵鄂辽晋B、皖晋辽豫C、黔皖辽豫D、贵皖豫辽①②③④ ⑤ ⑥⑦⑧⑨二、读图题1、读 "中国政区图"，回答问题（1）省区的名称： ①________ ②________ （2）省区的简称： ③_________ ④________ （3）省区行政中心的名称：⑤ ________ ⑥________ （4）⑦⑧⑨中，东西跨经度最多的是_________，不是民族自治区的是__________，被北回归线穿越的是__________（写出省区的名称）。

高中语文《兼爱》知识要点及限时练一、挖空练习圣人（封建时代对君主的尊称）以（把）治天下为（作为）事者也【判断句】，必知乱之所自起（产生的地方），焉（于是）能治之；不知乱之所自起，则不能治（治理）。

譬（比）之如医之（主谓之间，取消句子独立性）攻（治疗）人之疾者然（这样），必知疾之所自起，焉（于是）能攻之；不知疾之所自起，则（就）弗（不）能攻。

治乱者何独不然（这样）？必知乱之所自起，焉（于是）能治之；不知乱之所自起，则弗能治。

圣人以治天下为事者也，不可不察（考察）乱之所自起。

当（同“尝”，尝试）察乱何自起【句式：宾语前置】起（于）不相爱。

臣子之不孝（孝敬）君父，所谓乱也。

子自爱【句式：宾语前置，爱自】，不爱父，故（所以）亏（使动用法，使受损失）父而自利（使动用法，使……受益）；弟自爱【句式：宾语前置，爱自】，不爱兄，故亏兄而自利；臣自爱，不爱君，故亏君而自利。

此所谓乱也。

虽（即使）父之不慈（形作动，慈爱）子，兄之不慈弟，君之不慈臣，此亦天下之所谓乱也。

父自爱也，不爱子，故亏子而自利；兄自爱也，不爱弟，故亏弟而自利；君自爱也，不爱臣，故亏臣而自利。

是（这，这是）何（为什么）也？皆起不相爱。

虽（即使）至天下之为（做）盗贼（偷窃和劫夺财物的人）者，亦然（这样）。

盗爱其室（家），不爱异室，故窃异室以（来）利（使动用法，使……受益）其室；贼爱其身（自己），不爱人，故贼（名作动，偷盗、抢劫财物）人以利其身。

此何也？皆起不相爱。

虽至大夫之相乱（使动用法，使……混乱，使……受到侵扰）家（卿大夫的封地）、诸侯之相攻国者，亦然。

大夫各爱其家（卿大夫的封地），不爱异家，故乱异家以利（使动用法，使……受益）其家；诸侯各爱其国，不爱异国，故攻异国以利其国。

天下之乱物（纷乱之事），具（完备、齐全）此而已矣。

察此何自起【句式：宾语前置，自何起】？皆起不相爱。

若使（假使）天下兼相爱，爱人若（像）爱其身，犹（仍然、还）有不孝者乎？视父兄与君若其身，恶（疑问代词，相当于“何”“怎么”）施（实行）不孝？犹有不慈者乎？视弟子与臣若其身，恶施不慈？故不孝不慈亡（同“无”，没有）。

数学限时练习(1) 一、选择题：1.已知0(x>0)f(x)=1(x=0)2x3(x<0)⎧⎪-⎨⎪-⎩，，，，则f{f[f(5)]}的值是DA. 0B.－1C.5D. －52.下列各题中两个函数表示同一函数的是C2 A.f(x)=x g(x)=，B.f(x)=x g(x)=，C.f(x)=x g(x)=，2x4D.f(x)=g(x)=x+2x2--，3.设f (x)=5，则f (x2)= CA.25C.5D.不能确定4.设2x+1f(x)=x3x+2-的定义域T，全集U=R，则C R T= CA.{x|x≤1或x≥2}B. {1，2}C. {－1，1，2}D. {x|x<1或1<x<2或x>2}5.某物体一天当中的温度T 是时间t的函数:T(t)=t3－3t+60，时间单位是小时，温度单位是0C ，t=0时，表示12:00 ，12:00之后t取值为正，则上午8时的温度是AA.8 0CB.18 0CC. 580CD. 1280C6.已知函数f (x)=3(x－2)2+5且|x1－2|>|x2－2|，则AＡ.f (x1)> f (x2)Ｂ. f (x1)= f (x2)Ｃ. f (x1)< f (x2)Ｄ.不能确定大小7.设M={x|0≤x≤2}，N={y|0≤y≤2} 给出下列四个图形，其中能表示从集合M到集合N 的函AB C D8.已知函数2x1(x0)y2x(x0)⎧+≤=⎨->⎩，，使函数值为10的x值为CA ．3或－3 B.3或－5 C.－3 D.3或－3或－5 9.若f (2x+1)的定义域为[1，4]，则f (x+3)的定义域为B A.[0, 1.5] B.[0,6] C.[0.5,1.5] D.[3, 4.5] 10.已知f (x)是奇函数，当x>0时，f(x)=x(1－x)，则当x<0时，f(x)的解析式为B A.x(x+1) B.x(x －1) C.x(1－x) D.－x(x+1)二、填空题：11.已知A=B=R ，x ∈A ，y ∈B ，对任意的x ∈A ， x→2x 2+3是从A 到B 的函数，若输出４则应输入_________.12.已知函数y=－2x 2+3，x ∈{－2，－1，0，1，2}，则它的值域为 . 13.函数3x +1y =x 1-的值域为 . 14.已知f (x+1)=x 2－3x+2，则1f ()x的解析表达式为.15．函数y =_________.数学限时练习(2)姓名_________ 班级________ 一、选择题:1.单位圆中，面积为1的扇形所对的圆心角的弧度数为A.1B.2C. 3D.4 2.下列等式中恒成立的有 A.sin(α－β)=sinαcosβ－cosαsinβ B.cos(α－β)= cosαcosβ－sinαsinβ c1sin αcos β=[sin(α+β)sin(αβ)]2⋅--D.1sin αsin β=[cos(α+β)cos(αβ)]2⋅-- 3.)函数f(x)=sinxcosx 最小值是BA.－1B.－0.5C. 0.5D.1 4. sin5850的值为A.2-B.2C.2-D. 2 5.已知函数f(x)=sin(x －π2)(x ∈R),下面结论错误．．的是 A.函数f(x)的最小正周期为2π B.函数f(x)在区间π[0]2，上是增函数 C.函数f(x)的图象关于直线x ＝0对称 D.函数f(x)是奇函数6.已知tanα=4，cotβ=13，则tan(α+β)= A.711 B.711- C.713 D.713- 7下列关系式中正确的是A.sin110<cos100<sin1680B. sin1680 <sin110<cos100C. sin110<sin1680 <cos100D. sin1680<cos100 <sin110. 8. “πα=6”是“1cos2α=2”的 A.充分而不必要条件 B.必要而不充分条件 C.充分必要条件 D.既不充分也不必要条件9.函数2πy =2cos (x )14--是A.最小正周期为π的奇函数B.最小正周期为π的偶函数C.最小正周期为π2的奇函数 D.最小正周期为π2的偶函数10.函数f(x)=(1+的最小正周期为 A.2π B.3π2 C.π D.π2二、填空题：11.化简: ① cos580sin370+sin1220sin530＝ .② cos (α－β) cos(α+β) +sin(α－β) sin(α+β)＝ .12.已知113a (,2sin ),b (cos ,)322=α=α ，a //b ，则锐角α的值为 .13.函数y=cos2x －4cosx ，x []32ππ∈-，的值域是 .14.已知偶函数f(x)=2sin(ωx+φ)(ω>0，0<φ<π)的最小正周期是π，则f(x)的单调递减区间为 . 三、解答题：15. (07安徽)已知0π<α<4，β为πf(x)=cos(2x +)8的最小正周期， 1a (tan(αβ)1)4=+- ，，b (cos α2)= ，，且a b =m ⋅ ，求22cos α+sin2(α+β)cos αsin α-的值. 数学限时练习(3)班级_______ 姓名____________ 一、选择题： 1.在△ABC 中，若sinA cosB=a b，则B 的值为 A.300 B.450 C.600 D.9002.在△ABC 中，如果(a+b+c) (b+c －a)=3bc ，那么角A 等于A.300B.600C.1200D.1500 3.在△ABC 中，根据下列条件解三角形，其中有两个解的是A. b=10，A=450，C=700B. a=60，c=48，B=600C. a=7，b=5， A=800D. a=14，b=16，A=4504.在△ABC 中，若A=600，b=16，此三角形面积S=a 的值是A. B.75 C.51 D.495.在△ABC 中，sinA ：sinB ：sinC=3：2：4，则cosC 的值为A.23 B.－23 C.14 D.－146.已知三角形的两边长分别为4，5，它们夹角的余弦是方程2x 2+3x －2=0的根，则第三边长是 A.20 B.21 C.22 D.61 7.在△ABC 中，tanAsin 2B=tanBsin 2A ，那么△ABC 一定是A.锐角三角形B.直角三角形C.等腰三角形D.等腰三角形或直角三角形 8.已知锐角．．三角形三边分别为3，4，a ，则a 的取值范围为 A.1<a<5 B. 1<a<79.设A 是△ABC 中的最小角，且a 1cosA =a +1-，则实数a 的取值范围是 A.a ≥3 B.a ＞－1 C.－1＜a ≤3 D.a ＞0 10.如图：D ，C ，B 三点在地面同一直线上，DC=a ，从C ，D 两点测得A分别是β，α (α<β)，则A 点离地面的高度AB 等于 A.asin αsin βsin(βα)- B.asin αsin βcos(αβ)⋅-C.asin αcos βsin(βα)- D.acos αsin βcos(αβ)-二、填空题:11.在△ABC 中，A=60°, b=1，面积为3，则a +b +csinA +sinB +sinC= .12.在ΔABC 中，若ΔABC 1S 4=(a 2+b 2－c 2)，那么角∠C=______. 13.在ΔABC 中，A=600， c ：b=8：5，内切圆的面积为12π，则外接圆的半径为_____. 14.在ΔABC 中，a =5，b = 4，cos(A －B)=3231，则cosC=_______. 三、解答题:15.在海岸A 处，发现北偏东450方向，距离A 1n mile 的B 处有一艘走私船，在A 处北偏西750方向，距离A 为2 n mile 的C 处有一艘缉私艇奉命以的速度追截走私船，此时，走私船正以10 n mile / h 的速度从B 处向北偏东300方向逃窜，问缉私艇沿什么方向行驶才能最快追上走私船？并求出所需时间. (本题解题过程中请不要使用计算器，以保证数据的相对准确和计算的方便)北CBD三、解答题: 1.已知ΔABC 三个顶点的直角坐标分别为A(3，4)，B(0，0)，C(c ，0).(1)若AB AC =0⋅，求c 的值； (2) 若c =5，求sin ∠A 的值．2.已知△ABC 顶点的直角坐标分别为A(3，4)，B(0，0)，C(c ，0). (1)若c=5，求sin ∠A 的值； (2)若∠A 是钝角，求c 的取值范围．3.在△ABC 中，5cosA =13-，3cosB =5． (Ⅰ)求sinC 的值； (Ⅱ)设BC=5，求△ABC 的面积．4.设△ABC 的内角A ，B ，C 所对的边长分别为a ，b ，c ，且acosB=3，bsinA=4． (Ⅰ)求边长a ；(Ⅱ)若△ABC 的面积S=10，求△ABC 的周长l ．5.设△ABC 的内角A ，B ，C 所对的边长分别为a ，b ，c ，且acosB －bcosA=3c 5.(Ⅰ)求tanAcotB 的值； (Ⅱ)求tan(A －B)的最大值．6.在△ABC 中，角A ，B ，C 的对边分别为a ，b ，c ，tanC =(1)求cosC ； (2)若CB CA =2.5⋅，且a+b=9，求c ．7.在△ABC 中，内角A ，B ，C 对边的边长分别是a ，b ，c ，已知c=2，C=600．(Ⅰ)若△ABC a ，b ；(Ⅱ)若sinB=2sinA ，求△ABC 的面积．(Ⅲ)若sinC+sin(B －A)=2sin2A ，求△ABC 的面积．说明：本小题主要考查三角形的边角关系，三角函数公式等基础知识，考查综合应用三角函数有关知识的能力．数学限时练习(4)班级_______ 姓名____________一、选择题：1.若数列{a n }的通项公式是a n =2 (n ＋1)＋3，则此数列A.是公差为2的等差数列B.是公差为3的等差数列C.是公差为5的等差数列D.不是等差数列 2.设等差数列5，247，437…第n 项到第n+6项的和为T ，则|T|最小时，n= A. 6 B.5 C.4 D.33.在等差数列{a n }中，已知a 3=2，则前5项之和等于A. 10B.16C.20D.32 4.记等差数列{a n }的前n 项和为S n ,，若S 2n －1=(2n －1)(2n+1)，则S n = A.n (2n +1)2 B. n(2n+3) C.n(2n +3)2D. n(n+2) 5.等差数列{a n }中，若a 2+a 4+a 9+a 11=32，则a 6+a 7=A. 9B.12 C 15 D.16 6.等差数列{a n }中，已知前4项和是1，前8 项和是4，则a 17＋a 18＋a 19＋a 20=A. 7B. 8 C 9 D.10 7.已知等差数列{a n }的公差为1，且a 1+a 2+a 3+…+a 99=99，则a 3+a 6+…a 99=A. 99B. 66 C 33 D. 0 8.已知数列{a n }的通项公式为a n =2n －49，则S n 达到最小值时，n=A.23B.24 C 25 D.26 9.已知等差数列{a n }的前三项依次为a －1，a ＋1，2a ＋3，则此数列的通项 a n =A. 2n －5B.2n －3 C 2n －1 D.2n ＋1 10.已知等差数列{a n }的公差d ＝21，a 1＋a 3＋a 5＋a 7＋a 9＋…＋a 95＋a 97＋a 99=60， 则前100项之和S 100=A. 120B.145 C 150 D.170 二、填空题：11.{a n }为等差数列，a 4=－20，a 16=16，则|a 1|+|a 2|+|a 3|+…+|a 20|=________.12.等差数列{a n }中，若a 1＋a 3＋a 5=－1，则a 1＋a 2＋a 3＋a 4＋a 5=___________ .13.等差数列{a n }中，若a 2+a 3+a 4+a 5=34, a 2a 5=52, 且a 4＞a 2, 则a 5=_______. 14.数列前n 项和为S n =n 2+3n, 则其通项a n 等于____________.15.等差数列{a n }中, 前4项和为26, 后4项之和为110, 且前n 项和为340, 则n 的值为___________.16.等差数列{a n }中， S 5=28， S 10=36 (S n 为前n 项和)， 则S 15等于________.17.等差数列{a n }中，a 10<0， a 11>0， a 11>|a 10|， 若{a n }的前n 项和S n < 0，则n 的最大值是________.18.在1与9之间插入n －1个数b 1，b 2，…b n －1，使这n+1个数成等差数列，记为A n+1，则数列{A n+1}的通项公式为_____________. 19.若数列{a n }的前n 项和S n =3 n +1，则a n = ____________.20.若数列{a n }的前n 项和S n =2n 2－n+3，则其通项公式a n =_______. 21.数列lg21250⋅, lg 32250⋅, lg 43250⋅,……中，开始出现负值的项是第_____项. 22.凸n 边形的各内角度数成等差数列，最小角为1200 ，公差为50 , 则边数n 为_______.23.给出数阵如右图，其中每行、每列均为等差数列，则数阵中 所有的数的和为___________.24.设S n 是等差数列的前n 项和，已知3a 4=7a 7，且a 1>0，当S n 取得最大时，则n=________.0 1 2 (9)1 2 3 (10)2 3 4 ... 11 .................. 9 10 11 (18)。

四年级数学上册限时作业第一单元信息窗１《万以上数的读法》一、填空1、1０个一千是( ），10个一万是（），( ）个一千万是一亿。

2、从个位起,第5位是( ），第九位是（）。

3、和千万位相邻的数位是( ）和（）。

4、每相邻两个计数单位间的进率都是（）。

５、９0６7３40０0这个数中的３在( )位上,表示3个( ）,亿位上是( ）,表示( ）个（)。

二、读一读9372684读作：１７０654200读作：88５1800读作:13400０00000读作：三、判断1、从右边起，每一个数位是一级。

( ）2、79３００40中的“９”表示９个十万。

（）3、1０3005８读作一百万零三万零五十八。

（)4、一个数由3个亿,6个十万组成,这个数是3006000０0。

（）５、30７０００8０读作三百零七万零八十。

（）四、连一连四百二十八万三千七百五十６00６4000十四万零三十五4283750九千八百四十三万四千 984340００六千零六万四千 140０35四年级数学上册限时作业第一单元信息窗2《万以上数的写法》一、选择１、写含有三级的数时,先写( )。

Ａ.个级 B.万级 C.亿级2、写一千零五万三百一十时,需写出( ）个0。

A.2B.3 Ｃ.43、读作九千零一十万零八十的数是（)。

A.901０0８0 Ｂ．901００0８0 C.９０1008004、300０0+５00+９＝( ）。

A.350009 B.3０05009 C.3０5０9５、一个数由４个亿,７个百万,3个万和2个百组成，这个数写作( )。

A．４070３0２00 B．40７003200 C.4０703０0２0０二、写一写二百万写作:七千三百零五万零四十写作：二千零七万八千六百写作：九亿零四十二万八千写作:三、写出由下面各数组成的数。

1.七十万和三千( )2.八千万、四十万和五百（）3．九百万、六万和二十( )4.两千万、二万和二（）5.七千万、五十万、三千( ）第一单元信息窗３《万以上数的比较大小》一、在○里填上“>”、“<”或“=”。

高三英语晚自习限时练习一、阅读理解（本大题共3小题）AIf you are planning a tour to France, September is one of the best choices. Not only will you get to enjoy plenty of sunshine and warm weather, but the tourist season is beginning to wind down-which means cheaper airfares, lower prices at hotels, and fewer crowds. If this is your first trip to France , here is some handy information to help you!Visiting MuseumsMany museums in France have extended opening hours during the summer to adapt to the extra tourists from home and abroad, and some museums also have extended opening hours into September. Wandering around the Louvre（卢浮宫）will take you into a wonder world, where you can enjoy world- famous art. Going out of the Louvre, you can walk to the modem and fashionable Chumps Elysees to do some shopping.Taking a Cruise（乘船游览）The temperatures are slightly lower, but plenty of sunshine makes for perfect conditions to enjoy a barge cruise on the canals of France. Willi such comfortable weather and beautiful scenery at this time of year, nothing equals hanging out on the deck of a barge.Wine TastingSeptember is the beginning of the grape harvest season in France meaning there are plenty of wine- related events and festivals around the country. So September is a great time to visit the vineyards(葡萄园） around the country and go wine tasting. The Bordeaux, Loire and Burgundy regions are all lovely and great places to visit vineyards. Besides that, going to the castles of the Loire region between visiting vineyards on such warm and sunny days is also very enjoyable.Besides the above, riding a bike through France's villages is also a welcome activity for young visitors in September. So, don't hesitate and start to plan your September trip to France now.1. When do many French museums extend their opening hours?A．In Jan. & Feb.. B．In Apr. & May .C．In Aug. & Sep.. D．In Nov. & Dec..2. Where should you go if you want to visit both vineyards and castles?A．Bordeaux. B．Loire. C．Burgundy. D．Champs Ely sees.3. How do you like France in September?A．Warm but crowded. B．Cool but much noisy.C．Cold and less noisy. D．Sunny and less crowded.BAlice Roosevelt Longworth was the daughter of one of America’s most beloved presidents, Theodore Roosevelt. She was also a writer who was famous for giving high-society parties and being one of Washington, DC’s biggest gossips. On the sofa in herliving room, there was an embroidered cushion (绣花靠垫) which read, “If you can’t say anythi ng nice about someone, come sit next to me.”If Alice were still alive today (she died in 1980 at the age of 96), she would feelright at home with modern social media... at least the worst parts of it. Platforms such as WeChat and Weibo have become places where Internet troll and bullies hang around, spreading gossip and insults(侮辱), and causing real harm to people, especially young people. This phenomenon of social media bullying (cyberbullying) is a worldwide problem. In February, United Nations Internat ional Children’s Emergency Fund (UNICEF) declared a special day, Safer Internet Day, to raise awareness of the problem and to discuss ways to solve it. According to the organization, as many as 20 percent of young people say that they have been bullied online. And the effects of this bullying can be destructive, leading to lower grades, lower self-esteem, depression and even suicide. UNICEF’s Henrietta Fore says that the Internet has become “a kindness desert”.Closer to home, a study of Chinese high school students found that 58 percent had been bullied, and 38 percent had bullied someone either at school or on the Internet. “They spread rumors about you or defame you in order to isolate or marginalize(排斥) you,” says psychologist Zhou Zhonghui. “It is hard for people that age to bear, and it makes them depressed.”There are laws in China against cyberbullying, and offenders can be fined and have their accounts shut down. In fact, everyone can take steps to stop the bullying. First, don’t be silent. If you are being bullied, don’t hesitate to tell your parents and teachers. Second, think before you post. Is your comment kind or hurtful? Would you like someone to say the same thing about you? Would you like your mother to read your comment? Alice Roosevelt Long worth’s cushion was a humorous re-working of an old piece of wisdom: If you can’t say anything nice about someone, don’t say anything at all. By following that wisdom, you can make flowers bloom in the “kindness desert”.；4. By mentioning Alice Roosevelt Longworth in the first paragraph, the author intendsto .A．compare her to her fatherB．present the topic of cyberbullyingC．describe her achievementsD．recognize her way of life；5. What is Henrietta Fore’s tone when he discusses the Internet?A．Positive. B．Doubtful. C．Objective. D．Critical.；6. Which of the following is WRONG according to the passage?A．A majority of Chinese high school students have bullied others.B．Cyberbullying caused great harm to teenagers.C．Cyberbullying is no longer unique to Chinese students.D．A number of Chinese high school students feel depressed.；7. Which of the following has NOT been mentioned in the passage?A．The victims of cyberbullying.B．The solutions to cyberbullying.C．The consequences of cyberbullying.D．The causes of cyberbullying.CNatural silence — the kind when you hear nothing but the sound of nature around you — is becoming increasingly scarce. The noise of man-made can be heard even in the remote corners of national parks and deep in the Arctic Ocean.This is having some troubling effects. In humans, noise pollution has been linked to physical, mental health problems and cognitive impairment (认知功能障碍) in children. In wildlife,it’s disturbing navigation, pairing, communication and can cause hearing loss. “We’re losing the ability to listen to nature without noise pollution,” says sound recordist Matt Mikkelsen. He’s part of the non-profit organization Quiet Parks International, which aims to identify and preserve the planet’s last quiet places.Recently, this took him to Boundary Waters Canoe Area Wilderness in northeastern Minnesota. No cars, motor boats, electricity or telephone lines are allowed in the one-million-acre area,making it a strong candidate for Quiet Park status. But listening back to the recording, Mikkelsen can hear the low hum (嗡鸣声) of a commercial plane flying far away.Quiet Parks hasn’t yet decided if Boundary Waters meets its criteria —it’s one of 260 potential sites around the world that the organization is currently exploring. The te am will analyze the sound recordings from each location and consider them alongside other data.In recent years, the world has been getting louder, with cities and towns expanding and an increasing number of noises from cars, airplanes or ships. But during the COVID-19 pandemic (流行病), there has been momentary delay.In2020,global air travel was down by 60% and road transport decreased by almost half. Scientists in Europe found that noise caused by humans fell by up to 50% after lock downs were carried out.“People enjoyed the silence,” says Mikkelsen. “There were no airplanes in the sky and cars weren’t on the street. It was an incredible thing to be able to hear the world, all of a sudden, free from noise pollution,” he says. Since the start of the pandemic, Quiet Parks says it has experienced a huge increase in interest for quiet places. “I hope that we can take that desire for a world with less noise forward,” says Mikkelsen, “and appreciate the spots we have, where we can go and not experience noise pollut ion.”；8. What does the underlined word “scarce” probably mean in paragraph 1?A．Special. B．Rare. C．Common. D．Typical.；9. What is paragraph 2 mainly about?A．Causes of hearing loss.B．Tips on protecting the nature.C．Harmful effects of noise pollution.D．Unidentified problems from human beings.；10. What will Matt Mikkelsen’s team analyse according to the text?A．The sound recordings. B．Global air travels.C．Quiet Parks’ criteria.D．Data of the pandemic.；11. Where is the text probably taken from?A．A book review. B．A travel guide.C．A business plan. D．A science report.二、七选五阅读How to learn Wing Chun(咏春)Wing Chun is a style of kung fu that emphasizes close fighting, quick punches(击拳)and tight defense to overcome opponents. This traditional Chinese martial art is a complex kung fu method that requires years of practice to master. 12 .Learn the center line theoryA foundation of Wing Chun is the protection of your body’s center line. Imagine a line that starts at the middle top of your head and travels along the middle of your chest to the lower body. 13 . It must be protected at all times.Find a Wing Chun AcademyMartial arts schools often focus on one style of martial arts, especially for serious students. Wing Chun academies or clubs may be attached to a martial arts association. Search online or in a phone book for local Wing Chun schools. And then meet with the instructors and ask about their background. 14 .15Find an area in your house where you can practice Wing Chun. Make sure there is enough room for you to move your body around in all directions. Check by swinging your arms and legs around. You do not want your moves to be disturbed by furniture in the room.Find a partner to practice withLearning the movements on y our own will only take you so far. Eventually, you’ll need to start learning how your movements connect with an opponent. 16 . This person can also help encourage you and give you feedback on your form.A．Make a special space for practicing.B．Find a room equipped with furniture.C．Having a partner will give you good practice.D．So you have to find a good instructor to master it.E．But you can easily start learning it by the following tips.F．For example, how many years of experience do they have?G．This is the center line of your body that is vulnerable(易受伤的).三、完型填空I grew to be a tall girl but I tried to be as ordinary as possible. At school, I always chose a seat in the back of the room, and never 17 my hand in class. When I was 16, we were told that a new English teacher, Oliver Bascom, was going to teach us.Oliver Bascom! The girls laughed as we imagined a short and bald man. 18 , after we opened the door, there in front of the blackboard, we saw a young and 19 man!What followed was chaos, seventeen-year-old girls 20 to get to seats in the front of the room. And I managed to get a front and center desk.I really wanted to make a good 21 on my new teacher, but I usually kept quiet. One day we were given our first major 22 assignment. I worked the whole weekend on the essay and waited nervously for Mr. Bascom’s 23 .After three days, he arrived in class 24 the corrected papers. “I’ve 25 the ten best essays for class discussion.” he said. Twenty minutes later, my heart 26 when he got to the last essay and I didn’t hear my name.“These are all great essays,” Mr. Bascom continued. “ 27 , I am now going to read you the most success ful of all …” We were all surprised as this 28 work was written by me. That day a(n) 29 girl walked out of the classroom. I knew that I had a new set of standards to 30 and that anything was possible in the future. Finally, I 31 my head.17. A．brought up B．put up C．took up D．gave up18. A．Surprisingly B．Unfortunately C．Definitely D．Instantly19. A．serious B．strange C．handsome D．nervous20. A．pretending B．refusing C．slipping D．flying21. A．impact B．joke C．impression D．introduction22. A．writing B．reading C．speaking D．listening23. A．presentation B．evaluation C．celebration D．introduction24. A．forgetting B．lifting C．holding D．laying25. A．chosen B．left C．stuck D．rid26. A．attacked B．cheered C．jumped D．sank27. A．However B．Meanwhile C．Therefore D．Otherwise28. A．uncorrected B．unusual C．unwritten D．uncertain29. A．unique B．quiet C．ordinary D．different30. A．live up to B．look out for C．get hold of D．put up with31. A．turned B．raised C．dropped D．shook四、语法填空阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

孝感一中2021年高一下学期期末考试化学选择题专项限时训练三可能用到的相对原子质量：H-1 C-12 N-14 O-16Na-23 Mg-24 Al-27 S-32 Cl-35.5 Fe-56 Cu-64本题共16个小题，每小题3分。

在每小题给出的四个选项中，只有一项是符合题目要求的。

1．1869年，俄国化学家门捷列夫制出了第一张元素周期表，揭示了化学元素间的内在联系，成为化学史上的重要里程碑之。

下列有关元素周期表的说法正确的是A．元素周期表含元素最多的族是第IIIB族B．元素周期表有18个族C．第IA族的元素全部是金属元素D．前四周期称为短周期，其他周期称为长周期2．铯(13755Cs)可用于医学、工业测量仪器以及水文学。

下列关于13755Cs的说法正确的是A．质子数为55B．中子数为13C．质量数为192D．核外电子数为82 3．短周期主族元素X、Y、Z、W、Q 的原子序数依次增大，X 原子核外最外层电子数是其电子层数的2 倍，X、Y 的核电荷数之比为3∶4；。

W 与Y 形成的一种氧化物能使品红溶液褪色，Z 的原子半径是同周期主族元素中最大的。

下列说法正确的是A．原子半径大小：X＜Y，Z>WB．化合物Z2Y 和ZQY3都只存在离子键C．Q 的单质能从W 的氢化物中置换出单质WD．W 在自然界中只存在化合态，没有游离态4．下列排列顺序错误的是A．原子半径：Na＞P＞O B．热稳定性：HF＞HCl＞H2SC．碱性：KOH＞NaOH＞Mg(OH)2 D．酸性：H2CO3＞H2SiO3＞H3PO45．在下列变化过程中，既有离子键被破坏又有共价键被破坏的是A．将SO2通入水中B．火碱溶于水C．将HCl通入水中D．硫酸氢钠溶于水6．短周期主族元素W、X、Y、Z的原子序数依次增大，W的一种核素在考古时常用来鉴定一些文物的年代，W与Y同主族；X是地壳中含量最丰富的金属元素，Z原子的最外层电子数是其电子层数的2倍。

古诗文阅读板块限时练（一）(时间：30分钟满分：34分)一、文言文阅读(19分)阅读下面的文言文，完成1～4题。

赵尚宽，字济之，河南人，参知政事安仁子也。

知平阳县。

邻邑有大囚十数，破械夜逸，杀居民，将犯境，尚宽趣尉出捕，曰：“盗谓我不能来，方怠惰，易取也。

宜亟往，毋使得散漫且为害。

”尉既出，又遣徼巡兵蹑其后，悉获之。

知忠州，俗畜蛊①杀人，尚宽揭方书．．市中，教人服药，募索为蛊者穷治，置于理②，大化其俗。

转运使持盐数十万斤，谭③民易白金，期会促，尚宽发官帑．．所储副其须，徐与民为市，不扰而集。

嘉祐中，以考课．．第一知唐州。

唐素沃壤，经五代乱，田不耕，土旷民稀，赋不足以充役，议者欲废为邑。

尚宽曰：“土旷可益垦辟，民稀可益招徕，何废郡之有？”乃按视图记得汉召信臣④陂渠故迹益发卒复疏三陂一渠溉田万余顷又教民自为支渠数十转相浸灌而四方之民来者云布，尚宽复请以荒田计口授之，及贷民官钱买耕牛。

比三年，榛莽复为膏腴，增户积万余。

尚宽勤于农政，治有异等之效，三司使包拯与部使者交上其事，仁宗闻而嘉之，下诏褒焉，仍进秩赐金。

留于唐凡五年，民像以祠，而王安石、苏轼作《新田》《新渠》诗以美之。

徙同、宿二州，河中府神勇卒苦大校贪虐，刊匿名书告变，尚宽命焚之，曰：“妄言耳。

”众乃安。

已而奏黜校，分士卒隶他营。

又徙梓州。

尚宽去唐数岁，田日加辟，户日益众，朝廷推功，自少府监以直龙图阁．．．．知梓州。

积官至司农卿，卒，诏赐钱五十万。

(节选自《宋书·循吏传》) [注]①蛊：传说中一种人工培育的毒虫。

②理：司法衙署，狱官。

③谭：通“谈”，与……商谈。

④召信臣：西汉水利名臣，字翁卿，九江寿春(今安徽省寿县)人。

1．下列对文中画波浪线部分的断句，正确的一项是(3分)()A．乃按视图/记得汉召信臣陂渠故迹/益发卒复疏三陂/一渠溉田万余顷/又教民自为支渠数十/转相浸灌/B．乃按视图记得/汉召信臣陂渠故迹/益发卒复疏三陂一渠/溉田万余顷/又教民自为支渠数十/转相浸灌/C．乃按视图记/得汉召信臣陂渠故迹/益发卒复疏三陂一渠/溉田万余顷/又教民自为支渠数十/转相浸灌/D．乃按视图记/得汉召信臣陂渠故迹/益发卒复疏三陂/一渠溉田万余顷/又教民自为支渠数十/转相浸灌/解析：选C此类试题解答时，应先疏通大意，然后利用句中的人名、地名、官职名、文言虚词、句子结构以及语段中动词的宾语或补语等断句。

第三章第3讲(时间：45分钟分值：100分)一、选择题1。

[2013·广州一测］如果函数f(x）＝sin(ωx＋错误!）（ω〉0)的两个相邻零点之间的距离为错误!,则ω的值为( )A。

3 B。

6C. 12D. 24答案：C解析：T＝错误!，ω＝错误!＝12，选C项．2. [2012·大纲全国高考］若函数f（x)＝sin错误!（φ∈［0,2π]）是偶函数，则φ＝( )A. 错误!B. 错误!C. 错误!D。

错误!答案：C解析:∵f(x)为偶函数，关于y轴对称，x＝0为其对称轴．∴错误!＝错误!＋kπ，令x＝0，φ＝3kπ＋错误!π,当k＝0时，φ＝错误!π，选C项．3. 函数y＝tan（错误!x－错误!）的部分图象如图所示，则(O错误!－O错误!)·O错误!＝（）A。

－4 B。

4C. －2 D。

2答案：B解析：容易求得点A（2，0），B（3,1）,则(O错误!－O错误!）·O错误!＝(1，1）·（3,1)＝4。

4。

[2013·惠州模拟]已知函数y＝sin x的定义域为［a，b］，值域为［－1，错误!],则b－a的值不可能是（）A。

错误! B. 错误!C。

π D. 错误!答案：A解析：画出函数y＝sin x的草图分析知b－a的取值范围为［错误!，4π]．35. ［2013·金版原创］若函数y＝2cosωx在区间［0，错误!］上递减，且有最小值1，则ω的值可以是( ）A。

2 B。

错误!C。

3 D. 错误!答案：B解析：由y＝2cosωx在［0，错误!π]上是递减的，且有最小值为1,则有f(错误!π）＝1，即2×cos（ω×错误!π）＝1⇒cos错误!ω＝错误!。

检验各数据，得出B项符合．6。

[2013·泰安质检]函数f（x)＝cos(2x＋错误!)(x∈R），下面结论不正确的是（）A. 函数f(x)的最小正周期为πB。