I felt it hard to keep up with my classmates. But when I want to _____, my teacher always encourages me to work harder.
Go and _____ why he did such things.
He has a toothache. He should see a _____.
Remember_____ the light when you leave.
- Alan, can you tell me the answer _____the question? - OK!
- Time is money. - But I think time is _____money.