—I regret _____ you that Mary was badly injured in the accident. —I can hardly believe my eyes. She is always so careful.

_____ by the killers whales, the whalers were able to make a successful kill.

______ the room, the nurse found the tape-recorder ______ . 

 Oliver climbed up the hill _____ swimming in the cold weather.

Bill suggested________a meeting on what to do for the Shanghai Expo during the vacation.