A、To show us that distress is what people call the pleasant kind of stress. B、To show us that people will feel eustress and dist

Many people often say there is more stress in today’s society than in the years past. In fact, these people are comparing our lives with that of the cave man, who didn’t have to worry about the stock market or the atomic bomb. They forget that the cave man worried about being eaten by a bear while he was asleep, or about dying of hunger — things that few people worry much about today.
    Actually stress is a normal state of affairs, and it’s important that people understand what they are talking about when they talk about stress. Whenever anyone experiences something unpleasant, for lack of a better word they say they are under stress. Yet there is such a thing as "pleasant stress" — as in the case of the Olympic winner at the moment of his glory, or a conductor as his orchestra performs particularly well. They are just sending out excitement, and they are giving off all the stress hormones exactly the same as they were in low spirits or had just heard of a death in the family. We call the pleasant or healthy kind "eustress" and the unpleasant or unhealthy kind "distress".
    Then how can people deal with stress? The secret is not to avoid it but to "do your own thing". It implies doing what you like to do and what you are made to do at your own speed. For most people, it is really a matter of learning how to live and how to behave in various situations. To decide: "Do I really want to take my father’s business or be a musician?" If you really want to be a musician, then be one.
Questions 16 to 19 are based on the passage you have just heard.
16. What can be inferred from the passage?
17. In which situation will you feel "eustress"?
18. What is the purpose of the passage?
19. According to the passage, how can people deal with stress?