You have to stay behind if your homework         before five o'clock.

--What about the pen you bought yesterday.-- It       well. I like it very much.

Mom, the telephone is ringing. I guess either you or Dad           on the phone.

Each time tourists travel to Beijing, they_______ the Forbidden City.

--- It’s difficult for the village children to cross the river for school. --- I think a bridge ________ over the river.