按要求完成下列句子。

1. My ruler is on the desk. (就画线部分提问)

    ____________________________ is your ruler?

2. His father is reading a book. (变成一般疑问句)

    _________ __________ ________ reading a book?

3. I can use a computer. (变成否定句)

    I ___________________________ use a computer.

4. Wu Yinfan is my good friend. (就画线部分提问)

    ____________________________ your good friend?

5. This is a chair. (变成复数)

    ____________________________.