[填空题]

Lung Cancer

1. The death rate due to cancer of the lungs has increased more than 800 percent in males and has more than doubled in females during the last 25 years. It is considerably higher in urban and industrial areas than in rural districts. There are many possible causes, but it is still controversial which are most blameworthy. Those factors which have been mentioned most frequently are the presence of foreign particles and other irritants in the air (smoke particles, smog, exhaust fumes), and the smoking of cigarettes and cigars.
2. Numerous studies have demonstrated a striking correlation between the death rate from lung cancer and smoking habits. Among heavy smokers — 21 to 30 cigarettes per day — the mortality rate from lung cancer is nearly 17 times the rate from nonsmokers. It is expected the death rate among women will increase as the present high rate of smoking among women has its effect.
3. Sometimes cases

[填空题]
1. The death rate due to cancer of the lungs has increased more than 800 percent in males and has more than doubled in females during the last 25 years. It is considerably higher in urban and industrial areas than in rural districts. There are many possible causes, but it is still controversial which are most blameworthy. Those factors which have been mentioned most frequently are the presence of foreign particles and other irritants in the air (smoke particles, smog, exhaust fumes), and the smoking of cigarettes and cigars.
2. Numerous studies have demonstrated a striking correlation between the death rate from lung cancer and smoking habits. Among heavy smokers — 21 to 30 cigarettes per day — the mortality rate from lung cancer is nearly 17 times the rate from nonsmokers. It is expected the death rate among women will increase as the present high rate of smoking among women has its effect.
3. Sometimes cases

[单项选择]

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 diff
A. have been going up and down.
B. have remained stable.
C. have increased.
D. have fallen.

[单项选择]
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 diff
A. death rates.
B. various cancers.
C. unfair social differences.
D. biological differences.