The old scientist took up walking as a regular form of exercise, which, of course, is of great to his heath.
| A．benefit | B．favor |
| C．sense | D．relationship |
— Beijing or Shanghai? What did you mean?
— We were talking about _______ go to college.
| A．how to | B．where to | C．whether to | D．when to |
When he was a boy, he used to go there and watched _______.
| A．repairing bicycles | B．to repair bicycles |
| C．bicycles being repaired | D．bicycles to be repaired |
Robert is said______ abroad, but I do not know what country he studied in.
| A．to have studied | B．to study | C．to be studying | D．to have been studying |
Beijing was attacked by such a terrible sandstorm ______few citizens had ever experienced before.
| A．and it was | B．as | C．that | D．which |
He______ on this paper for ten minutes but he______only about sixty words.
| A．will have worked, has written | B．worked, has written |
| C．has been working, has written | D．will be working, works |