动词填空 。
1. Someone _____________ (knock) at the door, go and see who it is.
2. It is unnecessary for you _______________ (take) an umbrella every day.
3. __________ ( talk) with your parents often is a good way to make them understand you.
4. Hurry up! The film _______ (start) at 7;00 , there's little time left for us now.
5. Many people cut down trees __________ (make) more money.
6. We should protect animals to prevent them from _______________ (disappear).
