用适当的代词填空。

1. I'm a nice girl. _____ mother likes me very much.

2. He's Chinese. _____ father is a worker.

3. I don't know _____ telephone number, Tom.

4. —Are you students?

    —Yes, _____ are.

5. Anna is a good student. _____ brother is Peter.

24岁女性，复视半年伴睁眼费力，晨轻暮重。近日双下肢亦感劳累后无力。首先应检查的项目是（）

A.血钾测定

B.胸部X线

C.头部CT

D.新斯的明试验

E.脑脊液检查