It was in the lab _______was taken charge of by Professor Harris ________they did the experiment.
| A．which；that |
| B．that；what |
| C．whom；that |
| D．which；where |
You should study the details of the policy before you sign it.
| A．in return | B．in advance | C．at ease | D．on purpose |
If we keep wasting so much energy, ________are that our oil wells will dry up and the environment will be destroyed.
| A．problems | B．difficulties | C．questions | D．chances |
You may imagine what great difficulty I had ________ complicated ideas in simple English.
| A．expressing | B．to express | C．expressed | D．express |
The incomes of skilled workers went up. ________，unskilled workers saw their earnings fall.
| A．Moreover | B．Therefore | C．Meanwhile | D．Otherwise |
The further falling of the stock market as reported today has ________ a fresh wave of selling.
| A．given off | B．set off | C．put off | D．got off |