A talk on American culture____in the school hall this weekend.
He looked around and caught a man _____ his hand into the pocket of a passenger.
Don’t leave the water ____ while you brush your teeth.
I don’t know whether you happen ____ it, but I’m going to study in the U.S.A. this September. A. to be heard B. to be hearing C. to hear D. to have heard
_____ and out of breath, we reached the top of the mountain and stopped _____ the beautiful scenery.
_____ in thought completely, he didn’t even know what was going on.