Beyond its influence on health，not getting enough sleep can lead to car accidents or other mistakes.Here are what sleep researchers have found about how to sleep.
     How much sleep do we actually need？
     It is known that all of us naturally need no less than eight hours of sleep per night.When we sleep below six hours per 24，we're at an increased risk of health problems.Some of us think we can make up any of those hours lost during the week on the weekends.Sadly there is no storage system for sleep in the brain.
Can we train ourselves to need less sleep？
    As a study in 1964，a 17-year-old boy named Randy Gardner stayed awake for 264 hours.How many people could do anything close to that without dying？
     When you are reading this，you might say you usually get six hours of sleep and feel just fine.Sleep experts often compare people without enough sleep to drunk drivers：They don't get behind the wheel thinking they're probably going to kill someone.
      Can we drink coffee instead of sleeping？
     Coffee can keep us awake.Remember，too much coffee may throw off our sleep and energy cycles.So limit coffee and avoid caffeine for four to six hours before bedtime.
     Does a sense or purpose connect to sleep quality？
     A new research suggests a kind of strong connection between purpose in life and sleep.People who have a greater sense of purpose usually have better physical and mental health，which in turn explains their higher-quality sleep.Perhaps developing a sense of purpose in life could be as useful at improving sleep as the healthy habits above.

How to sleep
Introduction	Not getting enough sleep can influence our health and （1） cause cause many mistakes.
Findings from （10） better better researchers	How much sleep do we actually need？	?Eight hours of sleep a night is（2） sleep sleep for all of us. ?Sleeping less than six hours a day can（3） necessary necessary the risk of health problems. ?It is（4） increase increase to make up the lost sleeping hours during the workweek.
	Can we train ourselves to need less sleep？	?People without enough sleep would insist that they were （5） impossible impossible but weren't doing well at all .
	Can we drink coffee instead of sleeping？	?Using coffee instead of sleeping might lead to sleep（6） fine fine .Drink proper amount of coffee at proper（7） mess/disorder mess/disorder .
	Does a sense of purpose connect to sleep quality？	?A sense of purpose in life is closely （8） time time with sleep quality. ?People with a greater sense of purpose may sleep （9） connected connected .