Some of us can decide to wake up at 6.30 am and sure
enough, we do, even without the help of the alarm clock.
We may be able to do that because our body has a regular
daily rhythm. We sleep about eight hours a day. Our
temperature fluctuates according to the time of the day
and so does the speed of our heartbeat. Scientists
were interested to find out whether this rhythm depends
on a sort of built-in clock in our body or daily changes
of light and darkness. They conducted two experiments.
In the first experiment, the volunteers were asked to
live alone in a cave, where they never saw daylight and
had no idea what time it was. They pitched and lived in
tents. Gas heaters, lights, books and a record-player
were provided to make life in the damp, chilly cave more
pleasant. No radios or newspapers were given. In the
second, the volunteers lived in specially built
underground apartments. The apartments were luxuriously
furnished. The volunteers in both the experiments
reported their daily routine to the scientists who were
stationed in camps above ground. They did this through
the use of a special telephone. Each experiment was
conducted over a period of three months.
The result of those experiments showed that most of
the volunteers slept and woke up regularly. Their days
lasted about twenty five hours. Only a few lived on
irregular schedules with some short days and some long
ones.
Scientists are sure that our body clocks exist.
However they have no idea where they are, what they look
like or what makes them run. Subconsciously, we can set
our clocks to run the way we want them to, according to
our schedules. |
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1. |
Why are we able to wake up at a specific time without help ? |
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2. |
How much sleep does an average person need ? |
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3. |
Why did the scientists conduct the experiments ? |
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4. |
How long did the experimenters stay in the
cave ? |
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5. |
Use two words to describe the cave. |
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6. |
Why were newspapers and radios not given to
the volunteers ? |
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7. |
Which sentence tells us that the volunteers
in the second experiment had more comfortable accommodation ? |
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8. |
What did the volunteers have to do every day
? |
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9. |
Was a day longer or shorter for most of the
volunteers in the experiments ? |
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10. |
What did the experiments prove ? |
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Answers |
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1. |
We are able to do that because our body has
a regular daily rhythm. |
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2. |
He needs about eight hours of sleep a day. |
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3. |
They wanted to find out whether the daily
rhythm depended on changes of light and darkness or on a sort of
built-in body clock. |
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4. |
They stayed there for three months. |
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5. |
It was cold and damp. |
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6. |
They were not supposed to know the time or
the day for the duration of the experiment. |
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7. |
The sentence is, 'The apartments were
luxuriously furnished.' |
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8. |
They had to report their daily routine to
the scientists. |
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9. |
It was longer. |
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10. |
They proved that body clocks exist and our
regular daily rhythm depends on them. |