The experiment shows that proper amounts of exercise ,if _______regularly, can improve our health.
Only after spending several nights working on the math problem to wonder whether the problem was wrongly set.
I can’t persuade him out of playing computer games. He is to them.
______ by a greater demand of vegetables, farmers have built more green houses.
It is reported that the floods have left about _________ people homeless.
When you get the paper back, pay special attention to what ________.