共用题干 第一篇

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 cancer itself, the report added.
"In general,black Americans have less hope of surviving five years after diagnosis
than 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 drop 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. Which may NOT be a reason for higher cancer death rates among U.S. blacks?

材料题

共用题干第一篇U. S. Blacks Hard-hit by CancerDeath 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

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材料题

共用题干第一篇U. S. Blacks Hard-hit by CancerDeath 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

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材料题

共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singulari

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材料题

共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singulari

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