答案解析
41正确答案为B.本题属于细节题，问的是NASA(美国国家航空航天局)设计新的航天飞机的目的是什么。文章第一句就指出了研发这种新的航天器的目的是取代现有的航天飞机，把航天员送到国际空间站去。所以正确答案为B.
42正确答案为C.
此题与4l题相连，问除了运送航天员这一主要使命外，航天飞机还用来干什么?原文第一句也回答了这个问题，那就是把它作为太空急救车，故C为正确答案。
43正确答案为A.此题问的是设计这架航天飞机表明了什么?选项A的意思是“NASA继续探索太空的决心”。其他几个选项的意思文中均与原文不符，所以A为答案。
44正确答案为D.此题为细节题，问的是NASA什么时候开始着手设计后续的航天飞机?原文第一段实际上已经提到，在调查哥伦比亚号失事原因之前，NASA就已着手开展工作了，倒数第三段第一句提到研制工作很多年前就开始了，故选D.
45正确答案为C.此题问的是10亿美元的款项被批准后用来干什么?选项A的意思是重建国际空间站，选项B的意思是颁发给在NASA工作的科学家，这两个选项都与原文意思不符。最后一段说，若10亿美元的款项获得国会的批准，这笔款项基本上平分给the
Orbital Space Plane和Next Generation Launch Technology这两个研究项目，故C为正确答案。
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(生物学)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(体格检查)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(发生率)，”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.