1. As a defense against air-pollution damage, many plants and animals_________ a substance to absorb harmful chemicals.
A. relieve B. release
C. dismiss D. disclose
2. As a matter of rule, the scrap value of a vessel can hardly be at ________ with the sound value.
A. par B. bearish
C. collapse D. rally
3. As a salesman, he works on a (an) ________ basis, taking 10% of everything he sells.
A. income B. commission
C. salary D. pension
4. As all of us know, color-blind people often find it difficult to ________ between blue and green.
A. separate B. distinguish
C. compare D. contrast
5. As everyone knows, the exchange ________ fluctuates almost daily.
A. ration B. ratio
C. rate D. interest
6 As far as the rank of position is concerned, an associate professor is ________to a professor, though they are almost equally knowledgeable.
A. attached B. subsidiary
C. previous D. inferior
7. As I was just getting familiar with this job, 1 had_________ to ask my boss.
A. many B. most
C. much D. more
8. As is well-known, knowledge is the __________condition for expansion of mind.
A. indispensable B. indefinite
C. inevitable D. impossible
9. As scheduled, the communications satellite went into _________ round the earth.
A. circle B. orbit
C. path D. course
10. As soon as it started to rain we turned round and _________ home.
A. made for B. called for
C. cared for D. searched for
