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 (免疫学家) 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 haft could not. 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 it- serf, 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 st
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
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 (免疫学家) 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 haft could not. 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 it- serf, 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 st
A. was strengthened
B. was not affected
C. was altered
D. was weakened
When we think about happiness, we usually think of something extraordinary, a peak of great delight--and those peaks seem to get rarer the older we get.
For a child, happiness has a magical quality. I remember making hide-outs in newly cut hay, playing cops and robbers in the woods, getting a speaking part in the school play. Of course, kids also experience lows, but their delight at such peaks of pleasure as winning a race or getting a new bike is unreserved.
For teenagers, or people under twenty, the concept of happiness changes. Suddenly it’ s conditional on such things as excitement, love, and popularity. I can still feel the agony of not being invited to a party that almost everyone else was going to. But I also recall the great happiness of being invited at another event to dance with a very handsome young man.
In adulthood the things that bring great joy--birth, love, marriage--also bring responsibility and the risk of loss. Love may not last,
A. he can realize what happiness is
B. he may not end up with happiness
C. he may consider it extreme happiness
D. he should not feel content with himself
我来回答: