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)
____________________________.