26. Why is the question of "how easily people can get used to working at night" no mere academic one?

　　A. Because few people like to reverse the cycle of sleep and wakefulness.

　　B. Because sleep normally coincides with the hours of darkness.

　　C. Because people are required to work at night in some fields of industry.

　　D. Because shift work in industry requires people to change their sleeping habits.

　　27. The main problem of the round-the-clock working system lies in_______.

　　A. the inconveniences brought about to the workers by the introduction of automation

　　B. the disturbance of the daily cycle of workers who have to change shifts too frequently

　　C. the fact that people working at night are often less effective

　　D. the fact that it is difficult to find a number of good night workers

　　28. The best solution for implementing the 24-hour working system seems to be_______.

　　A. to change shifts at longer intervals

　　B. to have longer shifts

　　C. to employ people who work on night shifts only

　　D. to create better living conditions for night workers

　　29. It is possible to find out if a person has adapted to the changes of routine by measuring his body temperature because______.

　　A. body temperature changes when the cycle of sleep and wakefulness alternates

　　B. body temperature changes when he changes to night shift or back

　　C. the temperature reverses when the routine is changed

　　D. people have higher temperatures when they are working efficiently

　　30. Which of the following statements is NOT TRUE?

　　A. Body temperature may serve as an indication of a worker's performance.

　　B. The selection of a number of permanent night shift workers has proved to be the best solution to problems of the round-the-clock working system.,

　　C. Taking body temperature at regular intervals can show how a person adapts to the changes of routine.

　　D. Disturbed sleep occurs less frequently among those on permanent night or day shifts.

　　26. D 27. B 28. C 29. D 30. B

　　Does a bee know what is going on in its mind when it navigates its way to 11 food sources and back to the hive, using polarized sunlight and the tiny magnet it carries as a navigational aid? Or is the bee just a machine, unable to do its mathematics and dance its language in any other way? To use Donald Griffin's term, does a bee have "awareness", or to use a 12 I like better, can a bee think and imagine?

　　There is an experiment for this, or at least an 13 , made long ago by Karl Von Frisch and more recently 14 by James Gould at Princeton. Biologists who wish to study such things as bee navigation, language, and behavior in general have to 15 their bees to fly from the hive to one or another special place. To do this, they begin by placing a source of sugar very close to the hive so that the bees (considered by their trainers to be very dumb beasts) can learn what the game is about. Then, at regular intervals, the dish or whatever is moved 16 farther and farther from the hive, increasing about 25 percent at each move. Eventually, the 17 is being moved 100 feet or more at a jump, very far from the hive. Sooner or later, while this process is going on, the biologists 18 the dish of sugar will find the bees are out there waiting for them, 19 where the 20 position had been planned. This is　an uncomfortable observation to make.

　　A. confirmed

　　B. phrase

　　C. next

　　D. shifting

　　E. observation

　　F. remote

　　G. progressively

　　H. confronted

　　I. distant

　　J. precisely

　　K. quotation

　　L. target

　　M. train

　　N. proficiently

　　0. investigation

　　II. I 12. B 13. E 14. A 15. M 16. G 17. L 18. D 19. J 20.