题目内容
（请给出正确答案）
What causes the central problem that so much water is wasted mainly by farmers？
A．Because farmers can use water for agriculture free.
B．Because agriculture uses 75% of the world"s water.
C．Because most farmers are not aware of water shortage.
D．Because too many thirsty crops are grown in dry countries.
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This conclusion does not depend on the unrealistic assumption that we can (56) tobacco. It merely assumes that we can reduce cigarette sales appreciably by raising prices or by (57) the type of education that already appears to have had a (58) effect on cigarette consumption by white-collar workers, and that we can substantially reduce the amount of tar delivered per cigarette. The practicability of preventing cancer by such measures applies not only in those countries, (59) the US, where, because cigarette smoking has been common for decades, 25～30 per cent of all cancer deaths now involve lung cancer, but also in those where it has become (60) only recently. In China, for example, lung cancer (61) accounts for only about 510 per cent of all cancer deaths. This is because it may take as much as half a century (62) the rise in smoking to increase the incidence of lung cancer. Countries where cigarette smoking is only now becoming widespread can expect enormous increases in lung cancer during the 1990s or early in the next century, (63) prompt effective action is taken against the habit--indeed., such increases are already plainly evident in parts of (64) .
There are four reasons why the prevention of lung cancer is of such overwhelming importance: first, the disease is extremely common, causing more deaths than any other type of cancer now does; secondly, it is generally incurable; thirdly, effective, practicable measures to reduce its incidence are already reliably known; and, finally, (65) tobacco consumption will also have a substantial impact on many other diseases.
51. A. hardly
B. never
C. less
D. reliably
What percentage of the earth'swater can man actually use at present？（）
A．Nearly 75 per cent
B．About 97 per cent
C．Exactly 3 per cent
D．Less than 3 per cent
What does the man say about complaints about travel agency？
A．They account for the largest proportion.
B．90 per cent of them are reasonable.
C．Most of them are for delayed air tickets.
D．Few of them are for poor accommodation.
What is the correlation between body weight and heart disease and blood pressure？
A．Ten per cent less body weight means ten per cent less risk of heart disease and high blood pressure.
B．Thirteen per cent more body weight means ten per cent more risk of heart disease and high blood pressure.
C．The more body weight one gains, the more risk of heart disease and high blood pressure he has.
D．The less body weight one gains, the more risk of heart disease and the less risk of high blood pressure he has.
What does the last sentence of the passage most probably mean？
A．The rainforest in the Central African Republic will be preserved forever.
B．The well-designed exhibit will be preserved as an artifact.
C．The exhibit reflects the hope that natural rainforests will be well preserved.
D．The exhibit of the rainforest in the museum is the sole one in the world.
What is the substance in cigarettes that causes cancer？
A．Cigarette ashes.
B．Nicotine.
C．Tar.
D．Not mentioned here.
According to the passage what causes tidal waves？
A．Earthquake.
B．Storms.
C．Seaquake.
D．Tides.
What is the best title for this passage？
A．The Causes of Industrial Revolution.
B．The Industrial Revolution and Its Significance.
C．The Theory of Division of Labour and Its Significance.
D．Adam Smith, the Economist and Philosopher.
What is the theme of the text？
A．The causes of low-wage problems.
B．The inequality of workers' pay.
C．The improvement of the rates of pay.
D．The economy and the rates of pay.
What are the possible causes of colony-collapse disorder given by the scientists？
A．Worsening environment.
B．Disease and chemicals.
C．Dwindling number of flowers around.
D．Changes in genes' structures.
