答案解析
41正確答案為B.本題屬于細節(jié)題，問的是NASA(美國國家航空航天局)設(shè)計新的航天飛機的目的是什么。文章第一句就指出了研發(fā)這種新的航天器的目的是取代現(xiàn)有的航天飛機，把航天員送到國際空間站去。所以正確答案為B.
42正確答案為C.
此題與4l題相連，問除了運送航天員這一主要使命外，航天飛機還用來干什么?原文第一句也回答了這個問題，那就是把它作為太空急救車，故C為正確答案。
43正確答案為A.此題問的是設(shè)計這架航天飛機表明了什么?選項A的意思是“NASA繼續(xù)探索太空的決心”。其他幾個選項的意思文中均與原文不符，所以A為答案。
44正確答案為D.此題為細節(jié)題，問的是NASA什么時候開始著手設(shè)計后續(xù)的航天飛機?原文第一段實際上已經(jīng)提到，在調(diào)查哥倫比亞號失事原因之前，NASA就已著手開展工作了，倒數(shù)第三段第一句提到研制工作很多年前就開始了，故選D.
45正確答案為C.此題問的是10億美元的款項被批準后用來干什么?選項A的意思是重建國際空間站，選項B的意思是頒發(fā)給在NASA工作的科學(xué)家，這兩個選項都與原文意思不符。最后一段說，若10億美元的款項獲得國會的批準，這筆款項基本上平分給the
Orbital Space Plane和Next Generation Launch Technology這兩個研究項目，故C為正確答案。
U.S.Blacks Hard hit by Cancer
Death rates for cancer are falling for all Americans.but black Americans are still more likely to die of cancer than whites，the American Cancer Society said MondayIn a special report on cancer and blacks，the organization said blacks are usually diagnosed with cancer later than whites，and they are more likely to die of the disease.
This could be because of unequal(不平等的)access to medical Care.Because blacks are more likely to have other diseases as well，and perhaps because of differences in the biology(生物學(xué))of the can cancer itself， the report added.
“In general，black Americans have less hope of surviving five years after diagnosis thail whites for all cancer sites and all stages of diagnosis.”the report said.
“In describing cancer statistics for black Americans，this report recognizes that many of the differences associated with race may be caused by unfair social and economic differences and unequal access to medical care.’
The cancer society said blacks should be encouraged to get check-ups(體格檢查)earlier，When cancer is more treatable.and it said more research is needed to see if biological differences play a role.
“The new statistics emphasize the continuing importance of wiping out these unfair socialdifferences through public policy and education efforts，”the organization said in a statement.
But it also noted a出op in cancer death rates.
“Cancer death rates in both sexes for all sites combined have dropped greatly among black Americans since 1992，as have incidence rates(發(fā)生率)，”said the report.
31 Black Americans arc more likely to die of cancer than
A people in other countries.
B white Americans.
C all other Americans.
D their ancestors.
32 Which may NOT be a reason for higher cancer death rates among US blacks?
A Unequal access to medical Care.
B Greater probability of having other diseases.
C Differences in the biology of the cancer.
D Early diagnosis.
33 Cancer is more treatable if it is.detected
A in an early stage.
B in a late stage.
C a110fa sudden.
D together with other diseases.
34 Public policy and education efforts may help to do away with
A death rates.
B various cancers.
C unfair social differences.
D biological differences.
35 Since 1992，cancer death rates among black Americans
A have been going up and down.
B have remained stable.
C have increased.
D have fallen.