Washing hands thoroughly is one of the effective ways to avoid ________ by virus.
| A．being infected | B．infecting |
| C．to be infected | D．to infect |
While________ along the road, Mr. Smith met an old friend of his.
| A．walked | B．he is walking | C．walking | D．is walking |
It was with the help of the local guide________ the mountain climber was rescued.
| A．how | B．who | C．when | D．that |
Either you or one of your students________ to attend the meeting that is due tomorrow.
| A．are | B．is | C．have | D．be |
Only when he apologizes for his rudeness________ to him again.
| A．I will speak | B．will I speak | C．do I speak | D．I speak |
---How about your job hunting?
---No luck. Now, I’ve reached the stage________ I don’t care what I do.
| A．which | B．when | C．where | D．that |