We must recognize that environmental health issues do not stop at city limits, county lines, state or even federal boundaries. We can no longer afford to be tunnel-visioned in our approach. We must visualize issues from every perspective to make the objective decisions. We must express our views clearly to prevent media distortion and public confusion.

　　I believe we have a three-part mission for the present. First, we must continue to press for improvements in the quality of life that people can make for themselves. Second, we must investigate and understand the link between environment and health. Third, we must be able to communicate technical information in a form that citizens can understand. If we can accomplish these three goals in this decade, maybe we can finally stop environmental degradation, and not merely hold it back. We will then be able to spend pollution dollars truly on prevention rather than on bandages.

　　16. We can infer from the first two paragraphs that the industrialists disregard environmental protection chiefly because ________.

　　A) they are unaware of the consequences of what they are doing

　　B) they are reluctant to sacrifice their own economic interests

　　C) time has not yet come for them to put due emphasis on it

　　D) it is difficult for them to take effective measures

　　17. The main task now facing ecologists, environmental activists and conservationists is ________.

　　A) to prevent pollution by legislation, economic incentives and persuasion

　　B) to arouse public awareness of the importance of environmental protection

　　C) to take radical measures to control environmental pollution

　　D) to improve the quality of life by enforcing environmental standards

　　18. The word “tunnel-visioned (Line 2, Para. 4) most probably means “________”.

　　A) narrow-minded

　　B) blind to the facts

　　C) short-sighted

　　D) able to see only one aspect

　　19. Which of the following, according to the author, should play the leading role in the solution of environmental problems?

　　A) Legislation and government intervention.

　　B) The industry’s understanding and support.

　　C) The efforts of environmental health professionals.

　　D) The cooperation of ecologists, environmental activists and conservationists.

　　20. Which of the following is true according to the last paragraph?

　　A) Efforts should be exerted on pollution prevention instead of on remedial measures.

　　B) More money should be spent in order to stop pollution.

　　C) Ordinary citizens have no access to technical information on pollution.

　　D) Environmental degradation will be stopped by the end of this decade.

　　參考答案：BBDCC

　　We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals too. In one experiment, for example, behavioral immunologist (免疫學家) Mark Laudenslager, at the University of Denver, gave mild electric shocks to 24 rats. Half the animals could switch off the current by turning a wheel in their enclosure, while the other half could mot. The rats in the two groups were paired so that each time one rat turned the wheel it protected both itself and its helpless partner from the shock. Laudenslager found that the immune response was depressed below normal in the helpless rats but not in those that could turn off the electricity. What he has demonstrated, he believes, is that lack of control over an event, not the experience itself, is what weakens the immune system.

　　Other researchers agree. Jay Weiss, a psychologist at Duke University School of Medicine, has shown that animals who are allowed to control unpleasant stimuli don’t develop sleep disturbances or changes in brain chemistry typical of stressed rats. But if the animals are confronted with situations they have no control over, they later behave passively when faced with experiences they can control. Such findings reinforce psychologists’ suspicions that the experience or perception of helplessness is one of the most harmful factors in depression.

　　One of the most startling examples of how the mind can alter the immune response was discovered by chance. In 1975 psychologist Robert Ader at the University of Rochester School of Medicine conditioned (使形成條件反射) mice to avoid saccharin (糖精) by simultaneously feeding them the sweetener and injecting them with a drug that while suppressing their immune systems caused stomach upsets. Associating the saccharin with the stomach pains, the mice quickly learned to avoid the sweetener. In order to extinguish this dislike for the sweetener, Ader reexposed the animals to saccharin, this time without the drug, and was astonished to find that those mice that had received the highest amounts of sweetener during their earlier conditioning died. He could only speculate that he had so successfully conditioned the rats that saccharin alone now served to weaken their immune systems enough to kill them.

　　11. Laudenslager’s experiment showed that the immune system of those rats who could turn off the electricity ________.

　　A) was strengthened

　　B) was not affected

　　C) was altered

　　D) was weakened

　　12. According to the passage, the experience of helplessness causes rats to ________.

　　A) try to control unpleasant stimuli

　　B) turn off the electricity

　　C) behave passively in controllable situations

　　D) become abnormally suspicious

　　13. The reason why the mice in Ader’s experiment avoided saccharin was that ________.

　　A) they disliked its taste

　　B) it affected their immune systems

　　C) it led to stomach pains

　　D) they associated it with stomachaches

　　14. The passage tells us that the most probable reason for the death of the mice in Ader’s experiment was that ________.

　　A) they had been weakened psychologically by the saccharin

　　B) the sweetener was poisonous to them

　　C) their immune systems had been altered by the mind

　　D) they had taken too much sweetener during earlier conditioning

　　15. It can be concluded from the passage that the immune systems of animals ________.

　　A) can be weakened by conditioning

　　B) can be suppressed by drug injections

　　C) can be affected by frequent doses of saccharin

　　D) can be altered by electric shocks

　　參考答案：BCDCA