第4部分：阅读理解（第31～45题，每题3分，共45分）下面有3篇短文后有5道题。请根据短文内容，为每题定1个最佳选项。
　　　　　　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 Monday． 
    In 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 social differences 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．