Baekeland and Hartmann report that the"short sleepers"had been more or less average in their sleep needs until the men were in their teens．But at about age 15 0r so，the men voluntarily began cutting down their nightly sleep time because of pressures from school，work，and other activities．These men tended to regard their nightly periods of unconsciousness as bothersome interruptions in their daily routines．

In general，these"short sleepers"appeared ambitious，active，energetic and cheerful．They stuck to their opinions，and were very sure about their job choices..They often held several jobs at once，or worked full-or part-time while going to school．And many of them had a strong urge to appear"normal"or"acceptable"to their friends and colleagues．

When asked to remember their dreams，the"short sleepers"did poorly．More than this，they seemed to prefer not remembering．Similarly，their usual way of dealing with psychological problems was not to admit that the problem existed，and then to keep busy in the hope that the trouble would go away．

The sleep patterns of the"short sleepers"were similar to，but less extreme than，sleep patterns shown by many mental patients categorized as manic （躁狂者）．

The"long sleepers"were quite different indeed．Baekeland and Hanmann report that these young men have been lengthy sleepers since childhood．They seemed to enjoy their sleep，protected it，and were quite concemed when sometimes they didn't have their desired 9hours of nightly bed rest．They tended to remember their dreams much better than the"short sleepers"．Many of the"long sleepers"were shy，anxious，quiet，nervous，passive，mildly depressed，and unsure of themselves （ particularly in social situations）．Several openly stated that sleep was an escape from their daily problems．

63．From the passage，we can leam that___．

A．"short sleepers"need less