There is a real possibility that these animals could be frightened, ______ a sudden loud noise.[ ]

The 70-year-old man ______ exercises in themorning.

What way are you thinking of ________ ridof this kind of pollution

The _____ of his clothes indicated tooclearly that he had been playing football

Emma can go out ________ school nights，but she must be back ________ ten o’clock． –Oh，I see．