About _______ gene-targeting drugs are already in testing pipeline. It won’t be long ______ they are put into effect.
| A．two dozen; before | B．two dozens; that |
| C．two dozens of; before | D．dozens; that |
Sam said the work would be done by December, _____ personally I doubt very much.
| A．it | B．that | C．when | D．which |
John thinks it won’t be long _________ he finishes the tough work.
| A．when | B．after | C．since | D．before |
Kathy, _________ for months to find a job as a typist, finally took a _________ at a local travel agency.
| A．struggling, condition | B．struggling, position |
| C．having struggled, position | D．struggled, condition |
I called Mary many times yesterday evening, but I couldn’t get through. Her brother _________ on the phone all the time.
| A．was talking | B．has been talking | C．had talked | D．talked |
some people regard as a disadvantage is seen as an advantage by many others.
| A．Whether | B．What | C．That | D．How |