You had better ______some time every day for sports so that you can keep yourself energetic.
Please don’t phone him between 1 and 3 p.m. tomorrow. He _________ a lecture then.
In a sport team each player has a clear role, and there are few occasions ______ members are confused or uncertain of their roles.
It is the test system, _____ the teachers, that is to blame for the heavy burden of middle school students nowadays.
With the help of his friends, he has _____a good business over the years.
Although it is ________ to watch programs on TV sometimes, I think people shouldn’t spend all the time watching it.