(2013·高考湖北卷)In much of the animal world，night is the time________for sleep－pure and simple.

After the heavy mudslide happened in Sichuan, hundreds of newspaper reporters were sent to ____ the natural disaster.

The Students’ Union was founded for the________of them.

---Is this car secondhand? ---On the contrary, it is ______ new. 

We’d better _____ some sports because sports can give us a perfect build and protect us from getting illness easily.