—What led to his success ?

—He succeed _____ working hard .

I’m sorry that I can’t help _____ trees because I am busy with the homework.

It’s important that he_____ English well.

. —Have you finished your composition?

—Yes, I _____it in twenty minutes.

.Slang words (俚语) are made _____ special groups,such as workers and musicians.

This is the book _____ the teacher spoke in class.

ST Petersbury was in ruins:_______fires burned everywhere.

.What is the way Tom thought of _______enough money to buy it ?

You are saying that everying should be equal, and this is _____ I agree.

Though _____ my opinion ,my mother didn’t say anything to show that she stood by me.