In this country, children under 12 must be _____ by an adult in public libraries.

Does Dave go to work by __ car every day —No, he sometimes takes __bus.

(2013·合肥模拟)—Go and have great fun! I will cope with　　　you leave to me properly. —Thanks a lot.

I was surfing the Internet my brother was doing his homework.

Would you mind closing the door It’s really too cold. — _________________.