Passage 2
We all know that the normal human daily cycle of activity is of some 7-8 hours’ sleep alternation with some 16-17 hours’ wakefulness and that, broadly speaking, the sleep normally coincides with the hours of darkness. Our present concern is with how easily and to what extent this cycle can be modified.
The question is no mere academic one. The ease, for example, with which people can change from working in the day to working at night is a question of growing importance in industry where automation calls for round-the clock working of machines. It normally takes from five days to one week for a person to adapt to a reversed routine of sleep and wakefulness, sleeping during the day and working at night. Unfortunately, it is often the case in industry that shifts are changed every week; a person may work from 12:00 midnight to 8:00 a.m. one week, 8:00 a.m. to 4:00 p.m. the next, and 4:00 p.m. to 12:00 midnight the third and so on. This means that no sooner has he got used to one routine than he has to change to another, so that much of his time is spent neither working nor sleeping very efficiently.
The only real solution appears to be to hand over the night shift to a number of permanent night workers. An interesting study of the domestic life and health of night-shift workers was carried out by Brown in 1957. She found a high incidence of disturbed sleep and other disorders among those on alternating day and night shifts, but no abnormal occurrence of these phenomena among those on permanent night work.
This latter system then appears to be the best long-term policy, but meanwhile something may be done to relieve the strains of alternate day and night work by selecting those people who can adapt most quickly to the changes of routine. One way of knowing when a person has adapted is by measuring his body temperature. People engaged in normal daytime work will have a high temperature during the hours of wakefulness and a low one at night; when they change to night work, the pattern will only gradually go back to match the new routine and the speed with which it does so parallels, broadly speaking, the adaptation of the body as a whole, particularly in terms of performance. Therefore, by taking body temperature at intervals of two hours throughout the period of wakefulness it can be seen how quickly a person can adapt to a reversed routine, and this could be used as a basis for selection. So far, however, such a form of selection does not seem to have been applied in practice.
Why is the question of “how easily people can get used to working at night” no mere academic one?
文章第二段第一、二句说到，自动化生产要求机器24小时不停地工作，工人也要分三班昼夜轮流 工作，因而人们设法适应这种情况是实际生活的需要。因此选项D是答案。C选项说“在某些行业要上夜 班”，并未提及倒班，所以不正确；选项A、B与文章没有关系。
The main problem of the round-the-clock working system lies in ________.
文中第二段指出工人们适应新的工作时间通常要5至7天，但“shifts are changed every week”，这就 导致了“workers spent neither working nor sleeping very efficiently”，选项 C符合。
The best solution to implementing the 24-hour working system seems ________.
第三段第一句说，“要真正解决这个问题似乎只有把夜班活交给一批固定干夜班的工人去干”。第 四段第一句又说，“这种专职干夜班的方法看来不失为最佳的长远之计”，故A项是正确的。
It is possible to find out if a person has adapted to the changes of routine by measuring his body temperature because ________.
根据第三段第三句，正常日班工作时工作效率高，体温也稍高。文章接着又说，改变工作安排之 后，有一个适应过程。体温变动模式也随着适应程度的变化而变化，效率高时体温也高一些。这一点还可 以从这一句最后的particularly in terms of performance中看出。而选项A不全面，没有指出体温变化与身体的 适应程度大体上一致这一点，也没有指出可以根据其工作好坏来判断。
Which of the following statements is NOT true?
最后一段第一句提到“...something may be done to relieve the strains of alternate day and night work by selecting those people who can adapt most quickly to the changes of routine”，缓解的方法是选择一些能够较快 适应这种作息时间改变的工人。