主语提问很简单，直接把
特殊疑问词替换上去(Who和What使用频率最高。）
这里是少许的例子：
1.I play the guitar in the classroom.(I为单数故用plays）
Who plays the guitar in the classroom?
2.They are watching TV.
Who are watching TV?
3.He likes red T-shirts.
Who likes red T-shirts?
4.She ate this ice cream.
Who ate this ice cream?
5.The man bought a new book.
Who bought a new book?
6.Blue is my favourite colour.
What's your favourite colour?
7.Cat is my favourite animal.
What's your favourite animal?
8.My sister has a camera.
Who has a camera?