easy, difficult, hard, important, possible, impossible, comfortable, necessary, better. the first, the next, the last, the best, too much, too little, not enough It s so nice to hear your voice. 听到你的声音真高兴。 It s necessary for you to lock the car when you do not use it. 当你不用车的时候,锁车是有必要的。
2) It s very kind of you to help us. 他帮助我们,他真好。 Kind, nice, stupid, rude, clever, foolish, thoughtful, thoughtless, brave, considerate(考虑周到的), silly, selfish(自私的) 例句: It was silly of us to believe him. 我们真愚蠢,竟然相信了他。 It seemed selfish of him not to give them anything. 他不给他们任何东西,这显得太自私了。
注意:1) 其他系动词如,look,appear等也可用于此句型 2) 不定式作为句子成分时,动词用单数形式。 3) 当不定式作主语的句子中又有一个不定式作表语时,不能用It is… to…的句型 (对)To see is to believe. 百闻不如一见。 (错)It is to believe to see.