用some/any填空。

1. There are _____ books on the desks.

2. —Are there _____ students on the playground?

    —No,  there aren't.

3. There isn't _____ water in the bottle.

4. —Can I ask you _____ questions,  Lucy?

    —Of course.

已知某点的应力状态如图a）所示，则该点的主应力方位应为图b）中哪一个图所示？（）

A.A

B.B

C.C

D.D