John ___ be a basketball player.He’s much too short.

--- Why didn’t you tell me the truth that day? --- I _______, but you ______ for Beijing.

 Maybe if I ________ science，and not literature then，I would be able to give you more help.(2011·北京)

Smith was overweight, so the doctor urged that not only ________ have less fat and meat, but also he ________.

It’s required that the students______ mobile phones in their school, so seldom ______ them using one.