资源简介

(共21张PPT)
人教版（2019）
英语 选择性必修三
Unit 2
HEALTHY LIFESTYLE
Discovering the rules
目录
Discovering the rules
01
Studying the rules
02
Applying the rules
03
Exercise
04
It is never easy to change bad habits.
总结规律：用形式主语It代替真正的to change bad habits符合英语表达习惯，避免句子头重脚轻、结构失衡; 如果作者有意将比较长的不定式主语放在句首，那么作者就是想要突出不定式的内容。
Discovering the rules
01
1
2
3
4
5
6
Discovering the rules
01
Grammar Points: 动词不定式作主语时的用法，要关注以下几点：
1. 动词不定式作主语时，谓语动词常用单数。例如：
To see is to believe. 百闻不如一见。
2. 作主语的动词不定式在句中的位置有两种：
(1) 动词不定式置于句首。
(2) 用it作形式主语，放在句首，把真正的主语——动词不定式置于句后。
3. 动词不定式通常有逻辑主语，一般用for/of短语来表示，即for/of sb to do sth,其中sb就是动词不定式的逻辑主语。
It is clever of you to work out the maths problem.
It is difficult for you to work out the maths problem.
Studying the rules
02
Grammar Points: 动词不定式作主语时的用法，要关注以下几点：
4. 疑问词和动词不定式构成的不定式短语，也可以作主语。疑问词包括疑问代词who、whom、what、which、whose以及疑问副词when、where和how。此外连接词whether也适用。 例如：
How to break the bad habit is the question. 如何改变坏习惯是个问题。
Where to go has not been discussed. 去哪儿还没有讨论。
It has not been decided whether to fly to Paris. 还没决定是否坐飞机去巴黎。
Studying the rules
02
It will take an hour for a nutrition specialist to make a balanced diet menu for you.
It is useful to turn to a fitness consultant for advice.
It is dangerous to take illegal drugs.
It is harmful to skip breakfast (too) often.
Studying the rules
02
归纳总结：it作形式主语的常用句型及其功能。
It is/was +形容词+ (for sb) to do sth 往往用于表达观点
It take/took/will take sb some time to do sth或 It is/was required for sb to do sth 往往用于陈述事实。
Studying the rules
02
常用于表示事物的特征，用于此句型的形容词有：easy, hard, difficult, possible, important, impossible, necessary, good, bad, exciting, interesting, surprising等。
1) It is ＋ adj. ＋for sb. to do sth.
sb. 是to do sth.的逻辑主语
It is +adj.+ for/of sb. to do sth.
Studying the rules
02
e.g. It is necessary for young students to learn a foreign language.
对年轻的学生来说，学习一门外语是必要的。
It is necessary for you to change your job.
你有必要换工作。
It was impossible for them to complete the task in such a short time.
他们不可能在这么短的时间内完成这项任务。
It’s important for us to keep the water clean.
保持水质清洁对我们来说是很重要的。
Studying the rules
02
常见的此类形容词有： kind, nice, wise, silly, polite, impolite, friendly, foolish, clever等。
2) It is＋adj.＋of sb.＋to do sth.
形容词用来表示不定式的逻辑主语(sb.)的性质、特征或品德
Studying the rules
02
e.g.
It was silly of you to give up such a good chance！
你放弃这么好的一个机会，真傻!
It’s very kind of you to say so.
你这样说真是太好了。
It is friendly of the family to try to make me feel at home in their house.
这家人对我很友好，使我在他们家里感到宾至如归。
It was rude of the boy to jump the queue!
那个男孩插队真是太无礼了!
Studying the rules
02
常见的名词有：pity, shame, pleasure, one’s duty, one’s job, fun, joy, good manners, bad manners等。
It is + n. + (for sb.) to do sth.
e.g. What a pity it is for you to have missed such a wonderful film.
真遗憾你错过了这样一个精彩的电影。
It must be great fun to fly to the moon in a spaceship.
乘宇宙飞船飞往月球一定很有趣。
Studying the rules
02
It takes/took/will take sb. some time/money to do sth.
做某事花费某人多长时间(钱)
e.g.
It took me more than an hour to do my homework yesterday evening.
昨天晚上我做作业用了一个多小时。
It will take us a lot of money to buy that house.
买那套房子要花费我们很多钱。
Studying the rules
02
be in control of
decide on
begin with
making a choice
made up my mind
Applying the rules
03
Exercise
Join the words to make full sentences, and then join the sentences to make a paragraph. You can add your own sentences if necessary to make your paragraph more meaningful.
1. important / avoid / passive cigarette smoking
It is important to avoid passive cigarette smoking.
n. 香烟
Exercise
04
2. will take / nutrition specialist / a balanced diet menu / make / an hour / for you
It will take the nutrition specialist an hour to
make a balanced diet for you.
3. useful / turn to / fitness consultant / for advice
It is useful to turn to the fitness consultant for
advice.
n. 专家
n. 顾问
Exercise
04
4. illegal / dangerous / take drugs
5. harmful / skip breakfast / often
It is illegal and dangerous to take drugs.
It is harmful to skip breakfast often.
n. 毒品，药品
v. 跳过
Exercise
04
Homework:
再次阅读Reading and Thinking板块的语篇，找出其他含有不定式的句子并将它们进行分类与归纳。
Exercise
04
Thank you!

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