It was nearly an hour __________ the sleeping pill __________ effect.
| A．when; took | B．before; took |
| C．since; takes | D．before; would take |
18．--- Tom has a lot of parties recently.
---Yes, that may ____ why he didn’t do well in the test.
A, sum up B. add up to C. account for D. make sense of
17．I’m ____a diet, since I put ____ weight easily.
| A．in; on | B．on; in | C．in; in | D．on; on |
16．He is heavily ____ now, so he can’t pay for a new house.
| A．out of debt | B．get into debt | C．in debt | D．get out of debt |
15．---Tom is never late for work. Why is he absent today?
---Something ________ to him.
| A．must happen | B．should have happened |
| C．could have happened | D．must have happened |
14．It is not who is right but what is right _______ is important.
| A．which | B．it | C．that | D．this |