What do they doing?是What do they like doing？

What do they like doing? 的意思是他们喜欢做什么。
They like swimming.
They like playing table tennis.
They like hiking.

问题本身就有问题，语法错误。
应该是What are they doing? 他们在做什么？
答案可以是：They are playing golf.
They are watching TV.
They are surfing on the internet.
They are reading newspaper.
或者what do they do?他们是做什么的？
They are bricklayers.
They are librarians.
They are policemen.
They are peacekeepers.

他们在做什么?不过问题错了,应该是What are they doing?
答案的话么,
比如：
They are playing.
They are cleaning.
They are watching TV.
They are helping with each other.
如果改问题的话,所有的are都改成like
帮你省点事,我再写一遍.
They like playing.
They like cleaning.
They like watching TV.
They like helping with each other.

他们在干嘛？
答案可以是：
They are playing basketball.
They are watching TV.
They are making plane modle