题目内容：
阅读下列短文,回答题.It is late at night and you are still awake. Should you take a sleeping pill( 药片) ? People who take medicine often come to depend on it. so you lie awake knowing that the new work day will soon arrive. If this happens to you for at least one month, you may have insonmia, or sleeping problems, at an early stage. There are millions of you.., us... around the world.
A new study led by Eric Nofzinger and Daniel Buysse of the University of Pittsburgh Medical School has found that you might fall asleep quicker and stay asleep longer if you try "cerebral hypo- thermia", which just means cooling down your brain. They examined twelve people who had in- somnia and twelve others who had no sleep problems. Each of them wore a soft plastic cap on their heads at bed time.
The caps had tubes(软管 ) inside filled with water. The researchers moved the water through the tubes and then changed the temperature of the water. As other studies showed that people who had trouble sleeping often had more chemical reactions ( 反应) in the front of their brains, the researchers thought lowering the temperature of the brain might help.
For the first two nights of testing, the patients wore no water caps. During the next two nights, the caps were worn, but the water was not cooled. Then the researchers cooled the water a little for two nights. on the final two nights of the study, the temperature of the water was made much cooler.
The researchers found that the water caps did not help the insomnia patients until the tempera- ture was about 140C. Most of the patients fell asleep faster and slept better when the coolest water was moving around their heads,
People might suffer from an early stage of insomnia if they A．become dependent on drugs
B．need to take medicine before sleep
C．stay up late worrying about their jobs
D．have difficulty falling asleep over a month
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