1. Those are all really important questions and very difficult to answer.句式“be + 形容词 + 不定式”意为“很……做某事……”如： This kind of work is easy to complete. 这种工作很容易完成2. I’m not sure how to answer them.不定式可以与疑问词 who, what, which, when, how, where 等连用，构成不定式短语，在句中作主语、表语、宾语和宾语补足语等如：Where to buy this kind of computer is a problem. 到哪里去买这种计算机是一个问题I really don’t know what to do. 我的确不知道该怎么办了 3. The important thing is not to stop questioning.这句话中的not to stop questioning 是动名词的否定形式，它由否定副词 not 加上动名词构成在这句话中，动名词用在系词后作表语如：He is worried about not going to the concert. 他担心的是不能参加音乐会。
To us students, the first task is studying hard. 对我们学生来说，第一任务就是努力学习4. In the dream, he grew a new type of rice that was as big as a peanut.句式as … as … 表示程度相同，第一个as是副词，后加形容词或副词的原级如：Jim is as honest as Billy. 吉姆和比利一样诚实She works as carefully as her sister. 她和她姐姐工作一样认真句式not as (so) … as 表示一方不如另一方如：I don’t run as (so) fast as you. 我不如你跑得快5. Since then, he has spent much of his time researching and developing new varieties.表示“花费”，可用于两个句式中：spend … on … 和spend … (in) doing …如：Each person spent about 100 yuan on food every month. 在伙食上每人每月花100元左右。
He doesn’t spend all his time (in) working. 他没有把全部精力用在工作上6. Before her illness, Helen was a bright and happy girl.before her illness是介词短语，意为“在生病之前”，在句中作状语我们可以用时间状语从句Before she was ill替换它这种介词短语作状语的句式可用从句进行替换如：Nothing can live without air or water. = Nothing can live if there is no air or water. 没有空气和水什么都不能生存7. With a lot of hard work, he found new ways to help people with T.B.—a disease that damages the lungs.其中to help people with T.B.—a disease that damages the lungs是动词不定式短语用在名词way后作定语不定式有时起形容词作用修饰名词或代词，在句中作定语。
不定式作定语时，它的位置在它所修饰的名词或代词之后如：作式词lo foress!_ ___________me to do is to cheer. Is there anyone to look after these children? 有人照看这些孩子吗？ Are there many places to see in Washington? 在华盛顿有许多可看的地方吗？如果不定式是不及物动词，或者不定式所修饰的名词或代词是不定式动作的地点、工具等，不定式后面应加上介词或副词如：There is nothing to worry about.没有什么可担心的 8. He once operated for sixty-nine hours straight without stopping.句中的without stopping 是介词短语作状语，修饰前面的动词operate介词without后加名词、代词、动名词构成介词短语作状语后可作状语，意为“没有……”。
如：She went to school without having breakfast. 她没吃早饭就去上学了9. To remember him, the government set up Bethune Medical School and the Bethune International Hospital in Shijiazhuang.句中的to remember him是动词不定式短语用在句首作状语，表示目的不定式作状语还可直接用在动词后如：Emma came to see me yesterday morning. 埃玛昨天上午来看我了To learn English well, she went to in England. 为了学好英语，她去了英国10. I told them that you made it for me.某些及物动词后面可以加两个宾语，一个表示人，叫间接宾语；一个表示物，叫直接宾语，它们和在一起称作双宾语双宾语在句子的位置有两种：主语 + 及物动词 + 间接宾语 + 直接宾语主语 + 及物动词 + 直接宾语 + 介词 to 或 for + 间接宾语如： He will make me a new kite. = He will make a new kite for me. 他要给我做一个新风筝。
Grandpa often tells us stories. = Grandpa often tells stories to us. 爷爷经常给我们讲故事。