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In today's world, sleep experts often say that for a better night's rest, Americans shouldtheir smartphones or iPads before sleeping. Such electronic products make the brain more active, and then influence their sleep. Buta latest survey, more than 90% of Americans often use computers or some other kinds of electronic products in the hour before bed.
Researchers find that man-made light from some electronic products at night may reduce (减少) the brain chemicals that help to sleep. In the study, the researchers let volunteers read, play games and watch movies on a screen for different periods of time while measuringlight their eyes received.
They found that two hours of sitting before a bright screen at night reduced the sleep chemical levels by about 22%.
Then the researchers studied the college students who often used computers at night. They got the similar results. And researchers say that may not only cause sleeplessness, but also raise the risk of obesity (肥胖症) , diabetes (糖尿病) and other diseases.
To be on the safe side, the researchers suggest that we should use computerbefore, or turn down our screens before sleeping.
Few peoplelike changing their habits, good or bad. Whether it is smoking, drinking orovereating, they1"enjoying" them to end.
On everypacket of cigarettes (香烟),people are warned against the2of smoking: "Warning: CigaretteSmoking Is Dangerous to Your Health."3,millions of them start smoking or go on smoking. Why?
Facts showthat families and surroundings (环境) play a very important part in4smokers. All those smokerscome from smoking families or have smoking5or relatives. Films and TVplays also play a part. People6their "heroes"on TV drinking alcohol (酒) or7cigarettes."Heroes" seem to fear8, neither killingthemselves nor killing others with alcohol and cigarettes.9theyare not afraid of the harm of smoking and drinking, why10commonpeople be afraid?
The simplewarning on the cigarette packet does not influence11habits.Even stronger warnings, like showing pictures of smokers who have died ofcancer, don't seem to12.
Knowingand believing seem to be two13things.
If smokingis really as14as doctors say, it is time for smokersto think about it and try to give it15!
