We young people shouldn’t _______ think about the failure (失败) in the past. Instead, we should be _______to face the future.
—Listen! Someone is playing ______ piano. —Wow! ______beautiful music! I like it very much
Our teachers always give us good advice. We should follow _________.
More money ____________ when we use both sides of paper.
---Where were you this morning? ---I _____________ in the supermarket.
Some animals can even see things ____________ in the dark.