The twins looked exactly the same.Even I couldn’t ___ one from the other.

stonished, Mum,” said my son to me the otherday, “that some people in the world ____be so ready to fight with others,addicted to killings.

Could you tell me____—Sorry，I have no idea.

The teacher asked a very difficult question. It was Ted who finally _____ a good answer.

There is somebody knocking at the door. Who________it be—I’m not sure. It ________ be a postman.