单项选择题

In the 1960s, medical researchers Thomas Holmes and Richard Rahe developed a checklist of stressful events. They appreciated the tricky point that any major change can be stressful. Negative events like "serious illness of a family member" were high on the list, but so were some positive life-changing events, like marriage. When you take the Holmes-Rahe test, you must remember that the score does not reflect how you deal with stress--it only shows how much you have to deal with. And we now know that the way you handle these events dramatically affects your chances of staying healthy.
By the early 1970s, hundreds of similar studies had followed Holmes and Rahe. And millions of Americans who work and live under stress worried over the reports. Somehow, the research got boiled down to a memorable message. Women’s magazines ran headlines like "Stress causes illness". "If you want to stay physically and mentally healthy", the articles said, "avoid stressful events."
But such simplistic advice is impossible to follow. Even if stressful events are dangerous, many--like the death of a loved one--are impossible to avoid. Moreover, any warning to avoid all stressful events is a prescription (处方) for staying away from opportunities as well as trouble. Since any change can be stressful, a person who wanted to be completely free of stress would never marry, have a child, take a new job or move.
The notion that all stress makes you sick also ignores a lot of what we know about people. It assumes we’re all vulnerable (脆弱的) and passive in the face of adversity (逆境) . But what about human initiative and creativity Many come through periods of stress with more physical and mental vigor than they had before. We also know that a long time without change or challenge can lead to boredom and physical and mental strain.
According to the passage, people who have experienced ups and downs may become ______.