3. It’s easier of you to take action if you wear red.

2. It’s silly for you not to take part in the party .

1. It’s difficult of me to finish his homework in five minutes.

4.The boy doesn’t shout to the old man. He is polite.

It_______ ______ ______ the boy ______ _____ ______ to the old man.

3.They look down on the poor. They are not right.

It’s ________ ______ ______ them ________ look down on the poor.

2. To learn the computer is useful.

　 ___________ _________ useful _______ ________ the computer.

1. It’s necessary that we read English every day.

It’s _________ ________ ______ ________ read English every day.

n　　　 It is important for us to protect the wildlife .

n　　　 It is harmful for us　 to pollute the environment .

n　　　 It is selfish of people to kill the wild animals .

n　　　 It is foolish of the farmers to change the farmlands to make more space for farms and buildings .

n　　　 It is wrong of the women to wear the clothes made of animal fur .

n　　　 It is necessary for us to help the wild animals.

3．of和for的区别： 将of或for 去掉，将表示sb的词作句子主语，表语不变，后接不定式，组成一个句子。若句子正确，则用of，若不正确用for。

Step 3 　Review:　 It’s + adj. + to do sth

It’s + adj. + for sb to do sth

It’s + adj. + that + 从句

注意：用于for sb to do sth结构中的adj.通常是：important, necessary, possible, impossible, interesting, hard, difficult, easy, meaningful, harmful…

Step 4　 　Exercises.

2．一般有如下一些形容词：nice ,kind , silly , good , wise , clever , careless, polite , selfish , rude , thoughtful , wrong , stupid ,…