I can think of many cases ______ students obviously knew a lot of English words and expressions but couldn't write a good essay.
. The camera isn’t good enough; I want to change ______.
The teacher told us that the problem was not _____ easy and that we should think _____ over carefully.
It was a matter of _____ would take the position.
Sarah hopes to become a friend of _____ shares her interests.
_____ comes to see me, tell him I’m out.