4.It is healthy for us to eat fruit and vegwtable frequently.
对我们来说,经常吃水果和蔬菜是有益我们健康的
5.It is necessary for us to clean our teeth every day.
对我们来说每天刷牙是有必要的
6.It is interesting to talk with you.
和你聊天很有趣.
7.It is difficult to get there before dark. 天黑以前赶到那里很困难。
8.It is better to get up early. 早起会更好。