补全对话。
A : Daming, you look unhappy.What’s _____ _____ you ?
B: Oh...mm...nothing.
A : How are you getting on ____ your study these days?
B : Every subject is good _____ English.I failed the English exam.
A : Well, please don't ____ it
B :Mum...English is very useful,_____ it?
A :Yes.English is _____ by a ____ population in the world.
B :I think so, but is so hard. I’ll do my _____!