4) I don't mind as long as it doesn't rain. 只要不下雨就行了。 [短语归纳]
on condition that …在……的条件下 III.重点句型
Some byproducts of this process are called “greenhouse” gases, the most important one of which is carbon dioxide. 这个升温过程的一些副产品就叫 “温室”气体,其中最重要的就是二氧化碳. [解释]one/all/every/each/part… of which(whom)引导的定语从句，表示“他（它）们中的一个/所有/每/部分……” [典例]
1) I have three good friends, all of whom have emigrated to U.S.A.我有三个好朋友，他们都移民美国了。
2) Here are many kitties, two of which are yellow.这有许多小猫，其中两只是黄色的。 三、语法突破 It 的用法（2） [来源:学科网ZXXK] [来源:学,科,网] It[来源:学*科*网] 1）用作形式主语，代替由不定式或不定式复合结构，表示的真正主语 It is better to lose a friend than to do this.与其这样做到不如失去一个朋友。 It is fun for her to study, but it is difficult to study and work at the same time.对于她来 说学习是有趣的，可是要边工作边学习对她来说是困难的。 2）It +系动词+形容词（或名词）(+of It's very kind of you to call.你能给我打电话真/for +sb)+不定式短语。若要说明动是太好了。 词不定式的动作是由谁做的时候，It's difficult for us to understand what she said.后接for sb.。能用于这个句型的形我们很难理解她说的话。 容词有：difficult，hard，easy， possible，necessary， important等；如说明动词不定式的逻辑主语的性质、品质、特性时，后接of sb.。能用于这个句型的形容词有：nice，kind，wise，clever，foolish，stupid，用 作 引 导 词 bright，right，wrong，silly等。例如： 3）It takes/took sb. some time to do How long will it take you to complete the trip? sth表示“花费某人多少时间做某事”。例如： 完成这次旅行你要花多长时间？[来源:学科网] 4）It+ makes+宾语+宾补+不定式 。例如： It makes me uncomfortable to go swimming in such a cold day.在这样冷的天气里游泳，使得我非常不舒服。 5）It+ be+ time （for sb.）+不定式。 It's time for us to go to school我们该去上学去例如： 了。 It's high time that Robert went to school.罗勃特该去上学的时间了。 6）It+系动词+形容词或名词+名词性从句（真正的主语是名词性从句）。用于此句型中的名词词组常It's a pity that I didn't think of it earlier.很可惜我没有早点考虑它。 It is necessary that the young learn to use the 见的有:a pity, a shame, no wonder, computer.青年人学习使用电脑是十分必要a fact, an pleasure, a surprise, 等；如果形容词是表示建议、命令、要求等意义，从句中的谓语动词常用动词原形或省略should.这类常见的形容词有:necessary, important, possible, strange, good, lucky, interesting, glad,等。例如： 7）It+系动词+过去分词+名词性从It is said that (=People say that ) the meeting 的。 句。 常用于此句型的分词有：said, will be put off till next Friday.据说会议将推迟told, reported, known, announced, 到下周五举行。 expected, believed, thought, 等。 在表示建议、要求、命令等意义的It is known that(=People know that ) nothing is difficult if you put your heart into it.众所周知，被动句中，从句中的谓语动词常用(should) do形式。这类常见的过去分词有：desired， suggested， advised， requested， ordered，proposed， commanded等。例如： 8）It+系动词+现在分词+名词性从句。例如： 世上无难事，只怕有心人。 It isn't surprising that he should marry her.他娶她没有什么惊奇的。 It's inspiring that we've won the first three games.真令人鼓舞我们开头这三场比赛都赢了。 [来源:Zxxk.Com] 9）It+ look/seem/appear/ happen It happened that I knew which room she lived +that-clause。 此句型可转化为不定式结构，常见的此类动词有：seem, happen. appear. in.我碰巧知道他住哪间房。 It worried him that his hair has turned a little worry, white.使他烦恼的是他的头发变的有点白了。 It seems that he was late for the train.看来他没有搭上火车。 matter。例如： 10）真正的主语是动名词It + be + It was no use talking to them和他们谈论是没no +use(good，help)+doing sth.此句型中的it作形式主语，动名词作真正主语，适用于这个句型的形容词有：use，useless， good， worthwhile等。例如： 11）（在动词think，find，consider，He found it important to study the situation of feel，make，believe，expect等后）Russian他发现研究俄国形势是很重要的。 作形式宾语。例如： We consider it not useful to do it.我们认为做那事是没有用的。 This has made it necessary for agriculture and industry to develop very quickly.这就使得工 农业必须飞速发展。 有用处的。 It is no use asking him to come now. He is busy.请他现在就来是徒劳的，他很忙。 12）主语+谓语+it宾补+名词性从句。例如： They want to make it clear to the public that they do an important and necessary job.他们要向公众表明，他们的工作不但重要而且是必不可少的。 2.it引1）It +be的适当形式+时间+since从句 这个句型表示从since从句中的谓语动作发生以后到现在或过去所经过的一段时间，意为“自从??以来已多久了”。例如： It is(or has been)a year since returned home．我回家已有一年 。(当主句的表语是表示时间的累积数时，允许主句用现在一般时。本句不能改为:*I have returned home for a year．) It is a month since I called you up.我已有一个月未给你打电话了。(本句原意是：自从我上次给你打电话起，到现已有一个月了。) It is already a year since she was an engineer．她不当工程师已有一年。(不是“她当工程师已有一年”。) 导的几个容易混淆的句有： 型 2）It + be 的适当形式+时间+before从句 此句型中的时间一般为表示It won't be long before we meet each other．我们不久就会见面的。 It was not long before she recited those 一段时间的词语，如long，years，poems．没过多久她就背下了那些诗。 months，weeks，days，hours，minutes等。主句中的谓语动词用肯定式，意为“过多长时间才??”，主句谓语动词用否定式时，意为“没过多长时间就??”。如： 3）It +be的适当形式+时间+when从句 在这个句型中it指时间，而且表示时间的词语前没有介词(时间一般为具体时间)。主句中的谓语It was already 10 o'clock when we got home．当我们到家时已经十点了。 It will be midnight when they get there．他们到达那里时将会是半夜。 动词和从句中的谓语动词在时态上一般是一致的，主句是will be时，when从句用一般现在时代替一般将来时。如：
【考题印证】
1.（2012陕西卷）13. No matter where he is, he makes _____a rule to go for a walk before breakfast.
A. him
B this
C. that
D. it
【解析】D 。考查代词。所填词做使役动词make的形式宾语，真正宾语是to go for a walk，选D。
2.（2012全国II）9. Sarah made ______ to the airport just in time to catch her plane this morning. A. herself B. this C. that D. it
【解析】D。考查代词的用法。此处it是形式主语，代替后面的不定式短语。句意：Sarah今天早上成功地及时到达了机场赶上了她的航班。
3.（2012四川卷）2. New technologies have made ____ possible to turn out new products faster and at a lower cost.
A. that B. this C. one D. it
【解析】D。本题考查代词。题干为固定句型：make + it + adj. + to do。其中it作形式宾语，替代动词不定式to turn out new products faster and at a lower cost。句意为：新兴科技已经使得更快地、以更低的成本生产新产品成为可能。
【真题体验】
1.（2011天津卷,1We feel our duty to make our country a better place. A. it B. this C. that D. one
2.（2011山东卷,24）The two girls are so alike that strangers find ________ difficult to tell one from the other. A. it
B. them
C. her
D. that
3.（2011江西卷25）Why don?t you bring _____ to his attention that you?re too ill to work on? A. that
B.it
C.his
D.him