Sleep

    We all know that the normal human daily cycle of activity ¹ is of some 7-8 hours" sleep alternating with some 16-17 hours" wakefulness and that, broadly speaking, the sleep normally coincides with the hours of darkness ². Our present concern is with how easily and to what extent this cycle can be modified.

    The question is no mere academic one ³.The case, 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 insistently 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 midnight to 8 a. m. one week, 8 am to 4 pm the next ,and 4 pm to 12 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 ⁴, so that much of his time is spent neither working nor sleeping very efficiently.

    One answer would seem to be longer periods on each shift, a month, or even three months. Recent research by Bonjer of the Netherlands, however, has shown that people on such systems will revert to their normal habits of sleep and wakefulness during the weekend ⁵ and that this is quite enough 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 a corps of permanent night workers ⁶ whose nocturnal wakefulness ⁷ may persist through all weekends and holidays. An interesting study of the domestic life and health of night-shift workers was carried out by Brown. She found a high incidence of disturbed sleep, digestive disorder and domestic disruption among those on alternating day and night shifts, but no abnormal occurrence of these symptoms among those on permanent night work.

词汇：

 alternate /ɔ:l"tə: nət/ vi．交替，轮换

wakefulness/"weikfulnis/ n．醒着，不睡

coincide /kəuin"said/vi．同时发生；一致

modify /"mɔdifai/vt．改变；缓和

automation /,ɔtəmeiʃən/n．自动化

insistently / in"sistəntli/adv．坚持地，执拗地；迫切地，急切地

reverse /ri"və:s /vt．使颠倒，使倒转

routine /ru:" ti: n/n．常规，例行公事

revert /ri"və: t/vi．恢复，回复

corps /kɔ:(r)/n．共同工作或活动的一群人；特种__，特殊军种

permanent /"pə:mənənt/adj．永久的，持久的

nocturnal /nɔk"tənəl/adj．夜间发生的

incidence /"insidəns/n．发生（率）

digestive /di"dʒestiv/adj．消化的，助消化的

disruption /dis"rʌpʃən/ n．混乱，分裂，崩溃

abnormal /æb"nɔ:məl/adj．反常的，变态的

occurrence /ə"kʌrəns/ n．发生，出现；（偶发性）事件

symptom /"simptəm/n．表征，征兆；病症，症状

注释：

1．…the normal human daily cycle of activity...：……人们每天正常活动的周期……

2．…the sleep normally coincides with the hours of darkness. .....睡眠时间通常与黑夜的长短相一致。

3．The question is no mere academic one．这不只是个简单的学术问题。

4．This means that no sooner has he got used to one routine than he has to change to another．这就意味着，他刚刚习惯了一种方式又不得不改为另一种。此句中的no sooner... than…倒装结构。no sooner+主语助动词倒装结构（has he...）的意思是“一……就……”，如：I had no sooner reached home than it began to rain．我刚到家天就下雨了。可以看出，只有当no sooner放在句首位置时，“主语一助动词”这一序列才发生变化。

5．…people on such systems will revert to their normal habits of sleep and wakefulness during the weekend.……在周末，按照这些体制工作的人会恢复他们通常的睡眠和清醒的习惯。

6．…a corps of permanent night workers...：……一组永久做晚班的工人……

According to the passage, the main problem about night work is that ________.

A:people hate the inconvenience of working on night shifts B:your life is disturbed by changing from day to night routines and back C:not all industries work at the same hours D:it is difficult to find a corps of good night workers

哪个命令用来创建/work目录（）

A:mkpoint/work B:mkmountpoint/work C:touch/work D:mkdir/work

All of the following are characteristics of a work package EXCEPT: （）.

A:It is a deliverable or project work component at the lowest level of each branch of the work breakdown structure B:It is a summary task at the top level of the WBS C:It includes the schedule activities required for completion of the deliverable or project work component D:It includes the schedule milestones required for completion of the deliverable or project work component

All of the following are characteristics of a work package EXCEPT:

A:It is a deliverable or project work component at the lowest level of each branch of the work breakdown structur B:It is a summary task at the top level of the WB C:It includes the schedule activities required for completion of the deliverable or project work componen D:It includes the schedule milestones required for completion of the deliverable or project work componen

Where do the woman’s parents work（）

A: They work in two different factories. B: They work in the same factory. C:Her father works in a factory, her mother works in a school.

"Low" work here means ______.

A:work with brains B:work with hands C:the work that people do at home D:the work scientists do in the lab

"Low" work here means ______.

A:work with brains B:work with hands C:the work that people do at home D:the work scientists do in the lab