Section ADirections: In this section, there is a passage with ten blanks. You are required
Section A
Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item with a single line through the center. You may not use any of the words in the bank more than once.
The normal human daily cycle of activity is of some 7-8 hours' sleep alternation with sane 16-17 hours' wakefulness and that the sleep normally coincides with the hours of darkness. Our present concern is with how easily and to what 【S1】______ this cycle can be modified.
The question is no mere academic one. The ease with which people can change from working in the day to working at night is a matter of growing importance in industry where 【S2】______ calls for round-the-clock working of machines. It normally 【S3】______ from five days to one week for a person to adapt to a 【S4】______ 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. This means that no sooner has he got used to one routine 【S5】______ be has to change to another, so that much of his time is spent 【S6】______ working nor sleeping very 【S7】______ .
One answer would seem to be longer periods on each shift, a month, or even three months. However, recent research has shown that people on such systems will 【S8】______ to go back to their normal habits of sleep and wakefulness during the weekend and that this is quite 【S9】______ to destroy any adaptation to night work built up during the week. The only real solution appears to be to hand over the night shift to those 【S10】______ night workers whose habit may persist through all week-ends and holidays.
A) reversed B) quickly C) than D) extent
E) permanent F) neither G) revert H) takes
I) level J) automation K) either L) enough
M) efficiently N) when O) spends
【S1】
题目内容
（请给出正确答案）
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
