下列哪项反射活动中存在着正反馈（）

A.腱反射

B.排尿反射

C.减压反射

D.肺牵张反射

E.对侧伸肌反射

用所给单词的适当形式填空.

1. How about _____ (play) soccer after school?

2. Why not _____ (buy)a nice belt?

3. Would you like _____ (have)a pair of sunglasses?

4. Let's _____ (go) to the movies.

5. Shall I _____ (open) the door?