21Because there is evidence of severely harmful effects from chemical dumps, the government has _____ tougher cleanup measures.
A.imposed
B.impulsed
C.implemented
D.incorporated
开始考试练习点击查看答案22A scientist does not accept statements which are not based on the most complete evidence available. Instead, he always checks, studies and makes experiments carefully and objectively to _____ them.
A.testifly
B.verify
C.affirm
D.assert
开始考试练习点击查看答案23It is due to the invention of the computer that man has been able to work so many wonders in the past few years. A case _____ is the successful launching of space shutle.
A.in point
B.in question
C.in a way
D.in brief
开始考试练习点击查看答案24Sometimes the tension produced by fears is so great that we cannot suppress it. At such times we need to _____ the tension by laughing or crying.
A.discard
B.disperse
C.disguise
D.discharge
开始考试练习点击查看答案25There are two great belts or _____ where ninety percent of all earthquakes take place; they may, however, happen anywhere at any time.
A.regions
B.areas
C.zones
D.districts
开始考试练习点击查看答案26One of the main goals of the modern wonmen's liberation movement, which started in the early 1960s, was to _____ sex discrimination in the workforce, and to open up careers for women that were previously reserved for men.
A.abolish
B.eliminate
C.diminish
D.extinguish
开始考试练习点击查看答案27Nowadays, skilled workers such as carpenters, electricians and TV repairmen often have higher income than college graduates. The old distinction that whitecollar workers make a better living than bluecollar workers no longer _____ true.
A.hold
B.stay
C.come
D.become
开始考试练习点击查看答案28The differences, in terms of lifetime experiences, between the average student who goes to college and the average student who does not, are so _____ to the collegegoing sutdnet that any student who can reach college owes it to himself to do so.
A.preferrable
B.favourable
C.convenient
D.compulsory
开始考试练习点击查看答案29An auction is usually advertized beforehand with full particulars of articles to be sold and where and when they can be viewed by _____ buyers.
A.perspective
B.prospective
C.prosperous
D.profitable
开始考试练习点击查看答案30Recently, great advances have been made in the study of Venus' surface by the use of radar waves to _____ the dense cloud layer.
A.persecute
B.pierce
C.penetrate
D.plunge
开始考试练习点击查看答案