Swan Lake is a famous ballet in four acts, ________ on a German fairy tale.
In big cities, some workers from the countryside have been tired of moving around and wish for a more ______ life.
Everything to do with ______ nature can have______ important part to play in the development of man.
---How do you find the film How to Train Your Dragon?— . I can’t think too highly of it.
The wise parents can tell whether their children are telling the truth____ they listen to their excuses to wrong deeds.
Doctors say that______ sleep may cause the students poor memory and concentration at school.