单选题
The normal human daily cycle of activity is of some 7~8 hours'sleep alternation with some 16—17 hours' wakefulness and that the sleep normally coincides【C1】______the hours of darkness. Our present concern is with how easily and to what extent this【C2】______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【C3】______of growing importance in industry where automation【C4】______round-the-clock working of machines. It normally【C5】______form five days to one week for a person to adapt to a【C6】______routine of sleep and wakefulness, sleeping during the day and working at night.【C7】______, 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【C8】______he has to change to another,【C9】______much of his time is spent neither working nor sleeping very【C10】______. One answer would seem to be【C11】______periods on each shift, a month, or even three months.【C12】______recent research has shown that people on such systems will revert to go back to their【C13】______habits to sleep and wakefulness during the weekend and that this is quite enough to destroy any【C14】______to night work built up during the week. The only real solution appears to be to hand over the night shift to those permanent night workers whose【C15】______may persist through all weekends and holidays.
单选题
【C1】
【正确答案】
B
【答案解析】解析：此处应选择B。此处指的是“睡眠常在夜间进行”。coincide with意为“与……一致，符合，暗合”。例如：My opinion eoineides with his．我的意见跟他的一致。
【答案解析】解析：此处应选择B。此句话的意思是：不幸的是，在制造业，每周都会倒班。四个选项的意思是：therefore因此；unfortunately不幸的是；in a word总之；in compari—son相比之下，比较起来。
单选题
【C8】
【正确答案】
D
【答案解析】解析：此处应该选择D。此句话的意思是：刚适应一个规则，就又要改变去适应另一个规则。no sooner…than…意为“一……就……”，常放在句首，表示强调，这时主句要倒装。例如：No sooner had he returned than he bought a house．他一回来就买了一套房子。