阅读理解 “Humans should not try to avoid stress any more than they would shun food, love or exercise.” Said Dr. Hans Selye, the first physician to document the effects of stress on the body. While here''s on question that continuous stress is harmful, several studies suggest that challenging situations in which you''re able to rise to the occasion can be good for you. In a 2001 study of 158 hospital nurses, those who faced considerable work demands but coped with the challenge were more likely to say they were in good health than those who felt they stress that you can manage also boost immune(免疫的) function. In a study at the Academic Center for Dentistry in Amsterdam, researchers put volunteers through two stressful experiences. In the first, a timed task that required memorizing a list followed by a short test, subjects through a gory(血淋淋的) video on surgical procedures. Those who did well on the memory test had an increase in levels of immunoglobulin A, an antibody that''s the body''s first line of defense against germs. The video-watchers experienced a downturn in the antibody. Stress prompts the body to produce certain stress hormones. In short bursts these hormones have a positive effect, including improved memory function. “They can help nerve cells handle information and put it into storage,” says Dr. Bruce McEwen of Rockefeller University in New York. But in the long run these hormones can have a harmful effect on the body and brain. “Sustained stress is not good for you,” says Richard Morimoto, a researcher at Northwestern University in Illinois studying the effects of stress on longevity,”It’s the occasional burst of stress or brief exposure to stress that could be protective.” “Humans should not try to avoid stress any more than they would shun food, love or exercise.” Said Dr. Hans Selye, the first physician to document the effects of stress on the body. While here''s on question that continuous stress is harmful, several studies suggest that challenging situations in which you''re able to rise to the occasion can be good for you. In a 2001 study of 158 hospital nurses, those who faced considerable work demands but coped with the challenge were more likely to say they were in good health than those who felt they stress that you can manage also boost immune(免疫的) function. In a study at the Academic Center for Dentistry in Amsterdam, researchers put volunteers through two stressful experiences. In the first, a timed task that required memorizing a list followed by a short test, subjects through a gory(血淋淋的) video on surgical procedures. Those who did well on the memory test had an increase in levels of immunoglobulin A, an antibody that''s the body''s first line of defense against germs. The video-watchers experienced a downturn in the antibody. Stress prompts the body to produce certain stress hormones. In short bursts these hormones have a positive effect, including improved memory function. “They can help nerve cells handle information and put it into storage,” says Dr. Bruce McEwen of Rockefeller University in New York. But in the long run these hormones can have a harmful effect on the body and brain. “Sustained stress is not good for you,” says Richard Morimoto, a researcher at Northwestern University in Illinois studying the effects of stress on longevity,”It’s the occasional burst of stress or brief exposure to stress that could be protective.”
文章大意：议论文。本文围绕“适度的压力对人体有益”展开议论。文章是典型的“总-分-总”三段体结构。第一段提出文章的主题——处于充满挑战的情形对人们是有好处的。第二段至第四段从三个不同的方面支持该主题：第一，做富于挑战性工作的人更健康；第二，适度的压力可以增强免疫功能；第三，瞬间的压力可以产生增强记忆功能的荷尔蒙。最后一段引用一位学者的话进行总结，与文章主题相呼应。

单选题 The passage is mainly about________

单选题 The word “shun”(Line 1, Para.1) most probably means________.

单选题 We can conclude from the study of the 158 nurses in 2001 that________

单选题 In the experiment described in Paragraph 3,the video-watchers experienced a downturn in the antibody because________.

单选题 Dr. Bruce McEwen of Rockefeller University believes that________.