--- I hear you have an experience in the Roya1 Air Force. Is that true？
--- Yes. I in the Royal Air Force for six years.
| A．served | B．had served | C．joined | D．have joined |
20. He was down with the flu, and ____ couldn’t come to the party.
| A．moreover | B．meanwhile | C．therefore | D．Otherwise |
19. At last he chanced to sail back towards the place _____ he had started.
| A．with which | B．for which | C．from which | D．on which |
18. My brother got fired a month ago, but he landed on his feet and found another job that paid ____ money.
| A．twice as much | B．as much twice | C．twice much as | D．as twice much |
17. I didn’t get into the two-hour quarrel; I know how it ______, though.
| A．would break out | B．has broken out | C．was breaking out | D．had broken out |
16.It is no doubt that once ____ this city, you’ll find that there is so much surprise waiting for you to discover.
visit B. visiting C. visited D. to visit