如何将SCH与DSN文件转化
今天非常高兴,总算把SCH文件转化为DSN文件成功,早就想在论坛里发点东西了,又怕没有技术含量.此次为了转化格式找资料大费周折,正好把这些步骤分享给大家,希望能为大家提供点便利,避免走我的弯路.
(一)怎么将Protel DXP的PCB板子转到Allegro。求完整的转换流程！
1 原理图
1.1 PADS logic(.sch) To orCAD(.dsn)
1.2 orCAD(.dsn) To PADS logic(.sch)
1.3 protel99se(.ddb）To orCAD(.dsn)
1.4 orCAD(.dsn) To protel99se（.sch）
2 PCB文件
2.1 PADS LAYOUT(.pcb) To allegro(.brd)
2.2 PADS和protel和P-CAD文件之间的转换可以用AD6.9完成
原理图
PADS logic(.sch) To orCAD(.dsn)
1.涉及软件：PADS logic 2007， AD6.9
2.步骤： 用PADS logic 2007打开.sch文件，export as--》select all 并选择2005.0版本点击ok存为.txt 打开AD6.9，Files--》import wizard--next--PADS ASCII design and library Files--add 类型 选择.txt--next...导入成功 在AD6.9的文件浏览窗口，右键点击.prjpcb, 选择project save as ，类型为.dsn即ok .
orCAD(.dsn) To PADS logic(.sch)
1.涉及软件：PADS logic 2007
2.步骤： 打开PADS logic，Files--》open类型选择.dsn,在工作目录中立即生成.sch 文件
protel99se(.ddb）To orCAD(.dsn)
1.涉及软件：AD6.9
2.步骤： 打开AD6.9，Files--》import wizard--next--99se ddb Files--next...导入成功 在AD6.9的文件浏览窗口，右键点击.prjpcb, 选择project save as ，类型为.dsn 即ok
orCAD(.dsn) To protel99se（.sch）
1.涉及软件：AD6.9，protel99se
2.步骤： 打开AD6.9，Files--》import wizard--next--orCAD and PADS design and library Files--next...导入成功 在AD6.9的文件浏览窗口，右键点击.schdoc文件，save as类型选择schematic binery4.0（.sch）文件 打开Protel99se,新建一个.ddb文件，将.sch 文件导入即可.
PCB文件
PADS LAYOUT(.pcb) To allegro(.brd)
1.涉及软件：PADS layout2007，allegro15.5
2.步骤： 导入前，请在allegro设置工作目录以及相应的library目录。打开allegro，Setup-user preferences 在Design_paths 中设置padpath和psmpath到自己的library
路径，在Config_paths中设置devpath和 materialpath到自己的library路径。 PADS layout 2007打开.pcb文件，Files-export, 请在format选择PADS layoutV2005.0，select all，在parts和nets打勾，ok即导出.asc文件 请将.asc文件copy到library路径 请在开始-程序-allegro SPB 15.5-PCB Editor Utilities-PADS translator（也可以打开allegro，Files-import-PADS-请在路径选择.asc文件。注意，务必将Options File选择安装路径下的pads_in.ini文件，如C:\Cadence\SPB_15.5\tools\pcb\bin\pads_in.ini）选择library路径下的.asc文件，ok。在library路径下会生成.brd文件和一些新的元器件封装描述的文件。.brd 文件为所需文件，其他文件可以删除。 PADS和protel和P-CAD 文件之间的转换可以用AD6.9完成.
(二)这里主要介绍把SCH转化为DSN的过程所需要主义的东西:
1.PADS2007的安装说明
2.如何激活PROTEL DXP2004
3.AD6.9安装过程以及破解文件详细请参考附件！
(三)因为现在在公司,不是很方便,以上各种用的软件.因为附件太大,暂不做上传。
如:1.1 PADS logic(.sch) To orCAD(.dsn)
1.2 orCAD(.dsn) To PADS logic(.sch)
1.3 protel99se(.ddb）To orCAD(.dsn)
1.4 orCAD(.dsn) To protel99se（.sch）
英语动词-ing形式作主语和宾语笔记整理 一、doing与不定式作主语 doing作主语—→通常用来强调一般的，长期的，习惯的事（物） Point: doing 作主语时常会用 it 作形式主语 E.g. It’s no use / good / fun doing sth. 这没什么用/好处/有趣做某事。 It’s a waste of time / money / energy doing sth. 这是浪费时间/金钱/精力做某事。 It’s a hard / good time doing sth. 这是（段）困难/美好的时光做某事。 不定式作主语—→通常用来强调具体的，暂时的，将来的事（物） 二、doing与不定式作宾语 部分及物动词（如：like , love , prefer）后接动宾时可接doing与不定式两种，两者所表达的含义有所不同：doing作宾语—→通常用来强调一般的，长期的，习惯的事（物） 不定式作宾语—→通常用来强调具体的，暂时的，将来的事（物） ★重点记忆 接动词-ing作宾语的及物动词（短语）： 顺口溜串联： 建议完成多练习，避免错过少延期 喜欢想象禁不住，承认否认与嫉妒 忍受保持不介意，逃脱冒险不原谅 接不定式作宾语的及物动词（短语）： 顺口溜串联： 一问三希望，碰巧拒绝同意， 决定假装提出承诺， 渴望设法买得起， 计划准备不失败。
接动词-ing / 不定式作宾语的及物动词： ①动词love , like , hate等后跟动名词和不定式作宾语，但接动名词表示经常性的情况，接不定式表示具体的动作 ②动词begin , start , continue等后既可跟不定式，又可以跟动-ing形式宾语，意义基本相同 ③一些动词后既可跟动名词做宾语又可以跟不定式作宾语，但意义上有很大差别： 三、动名词逻辑主语以及其他问题 ①动名词作主语时，形容词性物主代词one’s与名词所有格前置作动名词的逻辑主语，具体形式为：one’s doing ②动名词作宾语时，由形容词性物主代词one’s，人称宾格与名词所有格作动名词的逻辑主语，具体形式为：vt. One’s doing ③逻辑主语位于非谓语动词的最前面： E.g. his not being late. ④动词-ing的肯定形式： 一般时： 主动：doing 被动：being done 完成时： 主动：having done 被动：having been done ⑤动词-ing的否定形式： not + 动词-ing not + having done not having been done （注意：not 一定位于肯定形式的最前面） ⑥在need , want , require 等动词后接动名词，即用主动形式表示被动意义： need/want/require doing = need/want/require to be done
新希望英语语法精讲------“I t”作形式主语和形式宾语“It”作形式主语和形式宾语的用法详解 It作形式主语和形式宾语用法，是英语学习的主要语法项目之一。无论是单项选择，还是完行填空，it用法始终是反复考查的重、热点之一。现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考。一、 It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。 e.g. It is wrong to tell a lie. (说谎是错误的。) 〔It为to tell a lie 的形式主语〕 It is no use arguing about it. (争吵是没用的。) 〔It为arguing about it的形式主语〕 It is uncertain who will come. (谁要来还不确定。) 〔It为who will come 的形式主语〕 It 作形式主语的常见句型： ① It + be + 形容词 + to do sth. / doing / that …. e.g. It is very important to learn a foreign language. (学一门外语非常重要。) It is useless crying over the spilt milk. (覆水难收。)
It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。) ② It + be +名词词组 + doing / that …. e.g. It is no good telling lies. (撒谎没好处。) It is a pity that you didn’t go to see the film yesterday. (你昨天没看成那部电影真遗憾。) It is a truth that there would be no new China without the Communist Party. (没有共产党就没有新中国，这是毋庸质疑的。) ③ It + be + 过去分词 + that …. 该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc. e.g. It is said that they have invented a new type of computer. (据说他们发明了一种新型电脑。) It is believed that China will become one of the strongest countries in the world. (大家都相信中国将会步入世界强国之列。) It was reported that more than 170 thousand people died in the 2004 tsunami. (据报道，至少有十七万人在2004年那场海啸中丧生。) ④ It + seems / appears / happens等不及物动词 + that ….
it作形式主语和形式宾语的用法 it作形式主语和形式宾语的用法 It除了用作代词表示指代意义以外，还可以用作形式主语和形式宾语。这种用法是中学阶段英语学习的主要语法项目之一。纵观历届中考题，无论是单项选择、完型填空，还是句型转换或翻译，it用法始终是反复考查的重、热点之一。现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供读者学习和参考。 一、It 用作形式主语 1．当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it 只起先行引导作用，本身无词义。例如： It is wrong to tell a lie. 说谎是错误的。 It is no use arguing about it. 争吵是没用的。 It is uncertain who will come. 谁要来还不确定。 2．It 作形式主语的常见句型 ① It + be + 形容词+ to do sth. / doing / that ….。例如： It is very important to learn a foreign language. 学一门外语非常重要。 It is useless crying over the spilt milk. 覆水难收。 It was really surprising that she married a man like that.她嫁给那样的男士真让人惊讶。 ② It + be +名词词组+ doing / that ….，例如： It is no good telling lies. 撒谎没好处。 It is a pity that you didn’t go to see the film yesterday. 你昨天没看成那部电影真遗憾。It is a truth that there would be no new China without the Communist Party. 没有共产党就没有新中国，这是毋庸质疑的。 ③ It + be + 过去分词+ that ….：该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc.。例如： It is said that they have invented a new type of computer. 据说他们发明了一种新型电脑。 It is believed that China will become one of the strongest countries in the world. 大家都相信中国将会步入世界强国之列。 It was reported that more than 170 thousand people died in the 2004 tsunami. 据报道，至少有十七万人在2004年那场海啸中丧生。 ④ It + seems / appears / happens等不及物动词+ that ….。例如：
必修四unit2语法---Ving作主语和宾语强化训练题(带答案) 一.用所给动词的正确形式填空 （1） 1.Since then, ________(find) ways to grow more rice has been his life goal. 2.As a young man，he saw the great need for ________(increase) the rice output. 3.Yuan Longping searched for a way to increase rice harvests without ________(expand) the area of the fields. 4.However，he doesn’t care about ____________(be) famous. 5.He enjoys _______(listen) to violin music, ________(play) mah-jong，swimming and reading. 6.________(spend) money on himself or ________(lead) a comfortable life also means very little to him. 7.Just _______(dream) for things，however，costs nothing. 8.Over the past half century, ________(use) chemical fertilizers has become very common in farming. （2） 1.It’s no good ________(smoke)．You’d better give it up. 2.We are considering ________(visit) the Science Museum. 3.Did Jack admit _______________(take) some books without telling anybody? 4.Do you still remember ________(see) him this morning? 5.As a matter of fact，I didn’t mean ______________(argue) with you. 6.His _______(lose) bike made him very upset. 7.He’s been used to ________(go) to bed late. 8.I’m sorry for ________________(not，keep) my promise. 9.Does anybody imagine such a little girl __________(invent) this kind of machine? 10.I hear they’ve promoted Tom，but he didn’t mention _________(promote) when we talked on the
动词ing 做主语、宾语 It took the workmen only two hours to finish _______ my car. A. repairing B. repair C. to repair D. repaired 2. Have you forgotten ___$1000 from me last month? Will you please remember ____ it tomorrow? A. borrowing; to bring B. to borrow; bring C. borrowed; bringing D. borrowing; bringing 3. The classroom wants _____. A. clean B. cleaned C. to clean D. cleaning 4. Jack said that he wouldn't mind __for us. A. to wait B. wait C. waiting D. waited 5. My brother keeps ___ me with my work. A. to help B. help C. helping D. helped 6. We should often practice ___ English with each other. A. to speak B. spoke C. speak D. speaking 7. Keep on ____ and you will succeed. A. a try B. try C. trying D. trying 8. His parents insist on ___ to college. A. he should go B. he go C. his going D. him to go 9. The story was so funny that we ___. A. couldn’t help laugh B. can’t bu t laugh C. couldn’t help laughing D. couldn’t help but to laugh 10. Though it sounds a bit too dear (昂贵), it is worth ______. A. being bought B. buying C. to buy D. buying it 11. He devoted his life to _____ the atomic theory. A. study B. be studied C. studying D. have studied 12. We are both looking forward to __ next week. A. going on vocation(休假) B. go on vocation C. be going on vocation D. have gone on vocation 13. Y ou must pay attention to ___ the works of Lu Xun. A. read B. reading C. reader D. be read 14. Y ou should work tonight instead of _____ TV. A. to watch B. you watching C. you watch D. watching 15. The microscope is used for__ minute (微小的) objects. A. examining B. being examined C. examined D. examine 16. Mike has got used ___ up late at night.(stay up) A. to sit B. X C. to sitting D. sitting 17. Once the heart stops _____, death follows at once. A. beating B. to beat C. being beaten D. to be beating 18. We are now busy _____ for the examination. A. to prepare B. preparing C. prepared D. being prepared 19. I remembered ____ this person somewhere before. A. seeing B. having been seen C. seen D. to see 20. I regret ____ that to her. A. having said B. to have said C. to say D. /
2014-2015初中英语形式主语和形式宾语专项练习（有答案） 形式主语或形式宾语指的是：当不定式(短语)、动名词(短语)或从句在某个句子中作主语或宾语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语或形式宾语置于句首或句中动词之后，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。主要有: 一、it作形式主语 It 作形式主语的常见句型： ①It + be + 形容词+ to do sth. / doing / that …. e.g. It is very important to learn a foreign language. (学一门外语非常重要。) It is useless crying over the spilt milk. (覆水难收。) It was really surprising that she married a man like that. (她嫁给那样的男士真让人惊讶。) ②It + be +名词词组+ doing / that …. e.g. It is no good telling lies. (撒谎没好处。) It is a pity that you didn’t go to see the film yesterday. (你昨天没看成那部电影真遗憾。) It is a truth that there would be no new China without the Communist Party. (没有共产党就没有新中国，这是毋庸质疑的。) ③It + be + 过去分词+ that …. 该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc. e.g. It is said that they have invented a new type of computer. (据说他们发明了一种新型电脑。) It is believed that China will become one of the strongest countries in the world. (大家都相信中国将会步入世界强国之列。) It was reported that more than 170 thousand people died in the 2004 tsunami. (据报道，至少有十七万人在20XX年那场海啸中丧生。) ④It + seems / appears / happens等不及物动词+ that …. e.g. It seems that he enjoys pop songs very much. (似乎他非常喜欢流行歌曲。) It appears that Tom might change his mind. (看来汤姆可能会改变主意。) ⑤若句子是疑问形式，就只能用it作形式主语。 e.g. Does it matter much that they won’t come tomorrow? (他们明天不来很重要吗？) Is it true that he will go abroad next week? (他下周出国是真的吗？) ⑥It + takes + (sb.) + some time + to do sth. 这是一个表示“(某人)花多少时间干某事”的句型，其中it是形式主语，代替后面的不定式(to do sth.)，句型中的sb.也可以省略。 e.g. It took me some time to read the reading materials (我花了一些时间才读完那段阅读材料。) It took him fourteen hours to go to NewZealand from Shanghai by plane. (从上海乘飞机去新西兰花了他14小时。) How long does it take you to go to Beijing from Qingdao by train?
The -ing form as the Subject and the Object 教学设计 Contents 教学内容 Discovering useful structures(p.13); Using structures (p. 50) Teaching goals 教学目标 1,Enable students to use the –ing form as subject and object correctly and freely. 2.How to use the-ing form freely .Explaining , discussing and practicing . The importance and difficulties教学重点、难点 1. Inspire Ss to discover the differenxes. 2. Make Ss remenber the different predicate verbs. 课前导学 Discovering The following sentences are from the text. There are some useful structures in them . Let students translate them and pay attention to these boldface words . 1,he cares little about spending the money on himself or leading a comfortable life . (The Object) 2.He also doesn’t care about being famous. (The Object) 3.His other hobbies include playing mah-jong ,swimming and reading. 4.Wishing for things , however , costs noting .(The Object) 5.Since then ,finding ways to grow more rice has been his life goal . (The Subject) 6.As a young man , he saw the great need for increasing the rice output . (The Object) 7.Dr Yuan searched for a way to increase rice harvests without expanding the area of the fields .(The Object) 8.Dr Yuan awoke from his dream with the hope of producing a kind of rice that could feed more people .(The Object) 以学定教/展示激学 Teaching procedure Step 1 Warming up Have you ever seen these signs?
初中英语形式主语和形式宾语专项练习及used to do 的用法 三. 形式主语、形式宾语专项练习 1. It's easier _____ than ________. A. say;do B. to say;to do C. says;does D. saying;doing 2. It takes me 30 minutes ________ to school by bike every day. A. going B. to go C. goes D. go 3. It’s not easy ________ us _________ a foreign language. A. for; learning B. of; learning C. of; to learn D. for; to learn 4. Children find___ interesting to play computer games. A. that B. which C. it D. it’s 5. Do you think it important _____ computer well A. play B. plays C. to play D. playing
6. Is _______ necessary to complete the design before National Day A. this B. that C. it D. he 7. I don’t think _______ possible to master a foreign language without much memory work. A. this B. that C. its D. it 8. Does _______ matter if he can’t finish the job on time A. this B. that C. he D. it 9. Tom’s mother kept telling him that he should work harder;but _______ didn’t help. A. he B. which C. she D. it 10. _______ is a fact that English is being accepted as an international language. A. There B. This C. That D. It 11. I hate _______ when people talk with their mouths full.
新希望英语语法精讲------“It”作形式主语和形式宾语 “It”作形式主语和形式宾语的用法详解 It作形式主语和形式宾语用法，是英语学习的主要语法项目之一。无论是单项选择，还是完行填空，it 用法始终是反复考查的重、热点之一。现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考。 一、 It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it 只起先行引导作用，本身无词义。 . It is wrong to tell a lie. (说谎是错误的。) 〔It为to tell a lie的形式主语〕 It is no use arguing about it. (争吵是没用的。) 〔It为arguing about it的形式主语〕 It is uncertain who will come. (谁要来还不确定。) 〔It为who will come的形式主语〕 It 作形式主语的常见句型： ① It + be + 形容词 + to do sth. / doing / that …. . It is very important to learn a foreign language. (学一门外语非常重要。) It is useless crying over the spilt milk. (覆水难收。) It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。) ② It + be +名词词组 + doing / that …. . It is no good telling lies. (撒谎没好处。) It is a pity that you didn’t go to see the film yesterday. (你昨天没看成那部电影真遗憾。) It is a truth that there would be no new China without the Communist Party. (没有共产党就没有新中国，这是毋庸质疑的。) ③ It + be + 过去分词 + that …. 该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc. . It is said that they have invented a new type of computer. (据说他们发明了一种新型电脑。) It is believed that China will become one of the strongest countries in the world. (大家都相信中国将会步入世界强国之列。) It was reported that more than 170 thousand people died in the 2004 tsunami. (据报道，至少有十七万人在2004年那场海啸中丧生。) ④ It + seems / appears / happens等不及物动词 + that …. . It seems that he enjoys pop songs very much.(似乎他非常喜欢流行歌曲。) It appears that Tom might change his mind. (看来汤姆可能会改变主意。) ⑤若句子是疑问形式，就只能用it作形式主语。 . Does it matter much that they won’t come tomorrow (他们明天不来很重要吗) Is it true that he will go abroad next week (他下周出国是真的吗) ⑥ It + takes + (sb.) + some time + to do sth. 这是一个表示“（某人）花多少时间干某事”的句型，其中it是形式主语，代替后面的不定式（to do sth.），句型中的sb.也可以省略。 . It took me some time to read the reading materials.(我花了一些时间才读完那段阅读材料。)It took him fourteen hours to go to New Zealand from Shanghai by plane.(从上海乘飞机去新西兰花了他14小时。) How long does it take you to go to Beijing from Qingdao by train (从青岛坐火车到北京一般要花多久时间) I am not sure, but I think it takes at least nine hours to get there. (我不能肯定，但估计至少要九个钟头才能到那儿。) 二、It 用作形式宾语
it作形式主语和形式宾语 it既可作人称代词，用来表示动物或无生命的物体等，也可以作无人称代词，在句中作主语，表示“时间”、“距离”、“天气”等。它还可以引导强调句，使语气得以加强。此外，it在句中能作引导词，充当句子中的形式上的成分，如形式主语、形式宾语等。 ㈠it作形式主语：it作形式主语时没有具体的意义，而只是帮助把真正的主语移到句子后部去，使句子显得平稳一些。it作形式主语时，可以代替三种形式：不定式、动名词和主语从句。 1. it代替不定式短语常用于下列句型中： It + be +形容词+ (for/of sb.) to do sth. It + be + 名词+ to do sth. It takes sb. some time to do sth. 干…花了某人…时间 It’s up to sb. to do sth. 干…是某人的职责或义务 如：①It is everyone’s duty to obey the law.遵守法律是每个人的义务。 （it作形式主语, 代替不定式短语to obey the law） ②It is difficult for a foreigner to learn Chinese.对于一个外国人来说，学习汉语是困难的。 （it作形式主语, 代替不定式短语to learn Chinese） ③It is not right to use these places as rubbish dumps.把这些地方用来倒垃圾是不对的。 （it作形式主语, 代替不定式短语to use these places as rubbish dumps） ④It took them a year to build the bridge.建这座桥花了他们一年的时间。 （it作形式主语, 代替不定式短语to build the bridge） ⑤It is bad manners to stare at people.瞪着眼睛看人是不礼貌的。 （it作形式主语, 代替不定式短语to stare at people） ⑥It is up to us to help those in need.帮助那些有困难的人是我们的责任。 （it作形式主语, 代替不定式短语to help those in need） ⑦It is not up to you to tell me how to do my job.我怎样干我的工作不用你来多嘴。 （it作形式主语, 代替不定式短语to tell me how to do my job） ◆ It be + 形容词+ for sb. to do sth.与It be + 形容词+of sb. to do sth.： 如果句型中的形容词描述的是sb.的品质、品格，在逻辑上可以作sb.的表语，则sb.前应用介词of，否则就用for。如：①It’s n ecessary for us to use a short-wave radio to pick up the programmes.我们用一台短波收音机收听这些节目是必要的。
“It”作形式主语和宾语 It作形式主语和形式宾语用法，是中学阶段英语学习的主要语法项目之一。纵观历届高考题，无论是单项选择，还是完行填空，it用法始终是反复考查的重、热点之一。现将it 在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考。 一、It 用作形式主语 当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。 e.g. It is wrong to tell a lie. (说谎是错误的。) 〔It为to tell a lie的形式主语〕 It is no use arguing about it. (争吵是没用的。) 〔It为arguing about it的形式主语〕 It is uncertain who will come. (谁要来还不确定。) 〔It为who will come的形式主语〕 It 作形式主语的常见句型： ①It + be + 形容词+ to do sth. / doing / that …. e.g. It is very important to learn a foreign language. (学一门外语非常重要。) It is useless crying over the spilt milk. (覆水难收。) It was really surprising that she married a man like that. (她嫁给那样的男士真让人惊讶。) ②It + be +名词词组+ doing / tha t …. e.g. It is no good telling lies. (撒谎没好处。) It is a pity that you didn’t go to see the film yesterday. (你昨天没看成那部电影真遗憾。) It is a truth that there would be no new China without the Communist Party. (没有共产党就没有新中国，这是毋庸质疑的。) ③It + be + 过去分词+ that …. 该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc. e.g. It is said that they have invented a new type of computer. (据说他们发明了一种新型电脑。) It is believed that China will become one of the strongest countries in the world.
it作形式主语与形式宾语 形式主语 形式主语是动词不定式的一种，它也是逻辑主语, 可以把它归类到逻辑主语的第一种（不定式的逻辑主语）。用作宾语的不定式，用作目的状语的不定式，用作结果状语的不定式都是属于不定式的大概念里面的。 详细用法 综述 形式主语it 作为形式主语的it并无实际语义，只是为满足语法上的需要，避免句子头重脚轻，它代替的是句子的逻辑主语，概括起来会有如下情况： 句子的逻辑主语为不定式 如：It is very kind of you to give me a hand in time. It is my pleasure to address the meeting. It was pretty hard for him to bring up the child on his own. 句子的逻辑主语为从句 如：It so happened that the tickets were sold out. It is extremely obvious that she has been lying about her identity. It suddenly occurred to me that the message must have been hidden between the layers of the briefcase. 句子的逻辑主语为动名词短语 这类句子远不如前面两种出现率高，主要在（no good, waste, useless, no use, dangerous）等词语的后面用。 如：It is no use reasoning with him. It is no good reading in dim light. 作形式主语的代词只能用it，不能用that、this等词。例如: 1）It is easier to lose friends than to make friends. 交朋友难而失去朋友比较容易。 2）It is important for modern young people to master at least two foreign languages. 掌握至少两门外语对于当代年轻人来说是很重要的。 以上两句中的it是形式主语，真正的主语是后面的不定式短语。 3）It is considered no good reciting without understanding. 不理解的背诵被认为是没有好处的。 4）It is no use crying over spilt milk. 覆水难收。 以上两句中的it是形式主语，真正的主语是V-ing形式。 5）It is a fact that English is being accepted as an international language. 英语作为一门国际语言正日益为人们所接受，这是不争的事实。（it指代同位语从句） 6）It depends on the weather whether we will go. 我们去不去得看天气行事。（其中的
动词ing 形式作主语和宾语 一、动词ing 形式作主语 1.动词ing形式作主语往往表示经常性、习惯性的动作，谓语动词用单数。 Eg: Swimming is my favourate sport. 2.在It is no use/no good/useless/worthwhile/dangerous/a waste of time /fun等后需用动名词作 真正的主语。 It is no use waiting for him any longer. It is a waste of time arguing about it. 3.当句型“There is no…”表示“不允许、禁止某种行为的发生或存在”时，需用动名词作 主语。 There is no joking about such matters. 这种事开不得玩笑。 There is no point (in)doing sth 干…….没意义。 There is no sense(in)doing sth. 干…没道理/意义 【注意】当动名词做主语时，其逻辑主语由形容词性物主代词或名词所有格构成。 My sister’s being ill made us worried. 二、动词-ing形式作宾语 1.作动词的宾语。可接动名词作宾语的常见动词可用下面的口语记住： 避免错过少延期（avoid, miss, postpone） 建议完成多练习（advice, finish, practise） 喜欢想象禁不住（enjoy, imagine, can’t help） 承认否认与嫉妒（admit, deny, envy） 逃避冒险莫原谅（escape, risk, excuse） 2.英语中有一些动词短语也常跟v-ing形式作宾语。常见的跟v-ing形式作宾语的动词短语有insist on, object to, be good at, lead to, put off, give up, look forward to, feel like, devote to, get used to, pay attention to, be worth, be busy等。 He insisted on doing it in his own way. 他坚持要按自己的方法去做。 I have never dreamed of visiting that place. 我从未梦想过要参观那个地方。 3.有些动词或词组后跟动词-ing形式或不定式都可以，但意思不同。 Stop to do sth 停下来去做某事 Stop doing sth 停止做某事 Remember doing sth 记得做了某事 Remember to do sth 记住要去做某事 Forget doing sth 忘记做了某事 Forget to do sth 忘记要去做某事 Regret doing sth 后悔做了某事 Regret to do sth 遗憾要去做某事 Mean to do sth 想要做某事 Mean doing sth意味着做某事 Try to do sth 努力/企图做某事 Try doing sth 试着做某事 4.下列动词可接动词-ing形式的主动形式表示被动意义，相当于不定式的被动形式。 need / want/require/deserve doing=need/want/require/deserve to be done The lake needs repairing/ to be repaired