6、Judging from recent surveys, most experts in sleep
behavior agree that there is virtually an epidemic （流行病） of sleepiness in the nation．“I can’t think of a single study that hasn’t found
Americans getting less sleep than they ought to,” says
Dr．David．Even people who think
they are sleeping enough would probably be better off with more rest．
The beginning of our sleep-deficit
（lack） crises can be traced back to the invention of the light bulb a
century ago．From diary entries and our personal accounts
from the 18th and 19th centuries, sleep scientists have
reached the conclusion that the average person used to sleep about 9.5 hours a
night．“The best sleep habits once were forced on us,
when we had nothing to do in the evening down on the farm, and it was dark．” By the 1950s and 1960s, the sleep schedule had been reduced
dramatically, to between 7．5 and 8 hours, and most
people had to wake to an alarm clock．“People cheat in
their sleep, and they don’t even realize they’re doing it,” says Dr．David．“They think they’re okay because they can get by on 6．5
hours, when they really need 7.5, 8 or even more to feel ideally energetic．”
Perhaps the most merciless robber
of sleep, researches say, is the complexity of the day．Whenever pressures from work, family,
friends and community increase, many people consider sleep the least expensive
item on their programmed．“In our society, you’re considered dynamic if you say you need only 5．5 hours’ sleep．If
you’ve got to get 8．5 hours,
people think you lack drive and ambition．”
To determine the consequences of
sleep-deficit, researchers have put subjects through a set of
psychological and performance tests requiring them, for instance, to add
columns of numbers or recall a passage read to them only minutes earlier．“We’ve found
that if you’re in sleep deficit, performance suffers,” says Dr．David．“Short-term
memory is weakened, as are abilities to make decisions and to concentrate．”
1．What is the main topic of the passage?
A．Research on the causes and consequences of sleep-deficit．
B．The epidemic of sleepiness in the modern times．
C．The history of people’s
sleeping patterns．
D．The minimum of our sleeping hours．
2．Which of the following is Dr．David’s opinion?
A．People who think they
are sleeping enough are better off than those who don't．
B．Some people can remain
energetic with only 6．5 hours’
sleep a night．
C．If they get 8．5 hours’ sleep, people will be full of drive
and ambition．
D．People’s metal power suffers if they are lacking in sleep．
3．People in the 18th and 19th
centuries slept about 9．5 hours a night because _______．
A．they were forced by
their parents to do so
B．they knew what was
best for their health
C．they had no
electricity
D．they were not so
dynamic and ambitious as modern people are
4．The major cause of sleep-deficit of modern people is
_______．
A．the endless TV
programmed in the evenings and the internet
B．the heavy work load of
the day
C．the sufficient energy
modern people usually have
D．loud noises in the
modern cities
5．What does the word “subjects” in paragraph 4 mean?
A．Person or thing that
is being discussed or described．
B．Branch of knowledge
studied in a school．
C．Person or thing being
treated in a certain way or being experimented on．
D．Any member of a State
apart from the supreme ruler．