—O'Neal works hard.
—So he does.He is often seen ________ heavily before his teammates have even arrived at practice.
| A．to be sweated | B．sweated |
| C．be sweated | D．sweating |
Work hard when young, ______ you will regret.
| A．and | B．so | C．but | D．or |
It’s hot in the shopping mall, because the air-conditioning system ______.
| A．broke up | B．broke down | C．broke in | D．broke out |
--- It’s the fourth time that heavy smog(雾霾) has hit the city this month.
--- It’s high time we _______ measures to fight air pollution.
| A．will take | B．took | C．to take | D．taking |
Science has given clear evidence ______ smoking can lead to many diseases.
| A．what | B．which | C．that | D．where |
We admire this family, ______ the parents treat their child like a friend.
| A．why | B．which | C．where | D．that |