How much sleep do we need? People are all different. Some people need only three or four hours of sleep a night. Others need ten hours of sleep a night. Most Americans sleep seven to eight hours a night.
Some people find it is hard to fall asleep. About one in three Americans have a problem with sleep. Many of these people can not fall asleep. The name of this problem is insomnia (失眠症). Many famous people in history had insomnia. Some of these people have special (特殊的) ideas to make themselves sleep. Benjamin Franklin had four beds. He moved from bed to bed to fall asleep. Mark Twain lay (躺) on his side across the end of his bed.
根据短文内容，判断正 (T) 误 (F)。
Different people need different amounts of sleep (睡眠时间).
Most Americans sleep more than 8 hours a night.
If a person has insomnia, he can never fall asleep.
About 1/3 of Americans have a problem with sleep.
Mark Twain had four beds to make himself sleep.