Scientists say it may be five or six years _____ it is possible to test this medicine on human patients.
| A．since | B．after | C．before | D．when |
The teacher, together with his students, visiting the museum when the earthquake struck.
| A．was | B．were | C．had been | D．would be |
. ______ washing machine’s out of order, so I have to wash all our clothes by ______ hand.
| A．The … / | B．A … the | C．The … the | D．A … / |
Juliet Roberts, ______ predicted, won the award for the Oscar Best Female Actress.
| A．if | B．once | C．as | D．when |
. Partly ______ about his lost love, he buried himself in office work.
| A．forgetting | B．to have forgot | C．to forget | D．having forgot |
Learning to care for a pet helps a child grow into an adult who feels responsible for ______
dependent on him.
| A．who | B．those | C．ones | D．whoever |