41. As a _____ actor， he can perform， sing， dance and play several kinds of musical instruments.
A. flexible
B. versatile
C. sophisticated
D. productive
42. As a salesman， he works on a （an） _____ basis， taking 10% of everything he sells.
A. income
B. commission
C. salary
D. pension
43. As an excellent shooter， Peter practiced aiming at both _____ targets and moving targets.来源：www.examda.com
A. stationary
B. standing
C. stable
D. still
44. As teachers we should concern ourselves with what is said， not what we think _____.
A. ought to be said
B. must say
C. have to be said
D. need to say
45. As the plane was getting ready to take off， we all _____ our seat belt.
A. tied
B. locked
C. fastened
D. closed
46. At first， the speaker was referring to the problem of pollution in the country， but halfway in her speech， she suddenly _____ to another subject.
A. committed
B. switched
C. favored
D. transmitted
47. At no time _____ other countries.
A. China will invade
B. will invade China
C. will China invade
D. invade will China
48. Be here on Friday _____ the latest.
A. at
B. by
C. for
D. in
49. Because the whole country is in a financial dilemma， the government calls on us to _____ economy.
A. make
B. practice
C. carry
D. develop
50. Before he started the work， I asked the builder to give me an _____ of the cost of repairing the roof.
A. assessment
B. estimate
C. announcement
D. evaluation
51. Beryl hardly ever goes to _____ the cinema.
A. neither the theatre or
B. either the theatre nor
C. neither the theatre nor
D. the theatre or
