Teenagers their health because they play computer games too much.
| A．have damaged | B．are damaging | C．damaged | D．will damage |
A serious study of physics is impossiblesome knowledge of mathematics.
| A．against | B．before | C．beyond | D．without |
It was only after he had read the papersMr. Gross realized the task before him was extremely difficult to complete.
| A．when | B．that | C．which | D．What |
It may not be a great suggestion. But beforeis put forward, we'll make do with it.
| A． | a good one | B． | a better one | C． | the best one | D． | a best one |
The watch was very good, and he20 percent down for it.
| A． | paid | B． | cost | C． | bought | D． | Spent |
We very early so we packed the night before.
| A．leave | B．had left | C．were leaving | D．have left |