—I wonder what makes you a great teacher?
—I _______ as a tutor in my spare time at college, which contributes much to my today’s job.
| A．work | B．have worked |
| C．had worked | D．worked |
After Yang Liwei succeeded in circling the earth ,___our astronauts desire to do is walk in space .
| A．where | B．what | C．that | D．How |
we can not figure out ____quit a number of insects ,birds ,and animals are dying out .
| A．that | B．as | C．why | D．when |
The road is covered with snow. I can’t understand ________ they insist on going by motor-bike.
| A．why | B．whether | C．when | D．ho |
--Do you mind if I smoke here?
--____________.
A. Sure. Go ahead B. No. Go ahead C. Yes. Please
I hope there are enough glasses for each guest to have___________.
| A．one | B．不填 | C．them | D．to |