单词拼写。

1. That woman is my aunt.        brother is my father.

2. My father calls her sister and I call her         .

3. My mother calls him brother and I call him         .

4. His father's mother is his         .

5. Mary is David's sister and David is her         .

电压互感器副边的额定电压是（）

A.5V

B.10V

C.50V

D.100v