Not until World War II ______ to use new chemical techniques to purify penicillin.
| A．they managed | B．that they managed |
| C．did they manage | D．they didn’t manage |
We’re looking forward ___________the photo exhibition.
| A．to visiting | B．to visit | C．to having visited | D．visiting |
My radio ___, I have to share a radio with my desk-mate.
| A．repairing | B．repaired | C．being repaired | D．is being repaired |
The children were last seen ___ by the river.
| A．to play | B．played | C．play | D．playing |
He found himself ___ by the villagers.
| A．misunderstand | B．misunderstood | C．misunderstanding | D．was misunderstood |
The next morning people found the outside world completely ___.
| A．change | B．changed | C．changing | D．having changed |