Children’s brains can’t develop properly_______ they lack protein.
| A．when | B．since | C．because | D．unless |
Walking is a nice way to relax. ______, it can help reduce body weight if you do it regularly.
| A．However | B．Instead | C．Therefore | D．Besides |
Having decided to take the trip, he ______ preparing for it.
| A．set up | B．set about | C．set out | D．set aside |
—You mustn’t leave your car unlocked while you are away.
—No, I ______. Please don’t worry too much.
| A．can’t | B．mustn’t | C．won’t | D．needn’t |
I was caught in a traffic jam for over an hour, otherwise I ______ you waiting for such a long time.
| A．will not keep | B．have not kept | C．had not kept | D．would not have kept |
—Can I help you with it?
—I appreciate your ______, but I can manage it myself.
| A．advice | B．question | C．offer | D．idea |