A、Approaches to Get a Good Night’s Sleep. B、The Harm of Lack of Sleep. C、Effects of Modern Technology on Sleep. D、Benefits of a

Say you get into bed, prepared for a healthy seven or eight hours and then stare at the clock for four of them. Is all lost?(21)If you have trouble sleeping for a few days here and there, taking steps to improve your sleep should get you back on track. The first step for anyone with sleep problems should be to take a careful look at your sleep hygiene. This means organizing your surroundings and activities to promote sleep as bedtime approaches. Skip caffeine after noon. Avoid alcohol or heavy meals within three hours of bedtime.(19)Exercise is great for sleep, especially falling asleep. You’ll get the most benefit by exercising one or two hours before bedtime. A hot shower or bath about an hour and a half before bedtime can also be helpful. In addition, reserve your bed for sleep.(20)If you can’t sleep, get out of bed, go somewhere else, do something quiet, calm and relaxing, go back to bed when you’re sleepy again. Go to bed and wake up at the same time—within a half hour—every day. Finally, don’t make your Facebook page, BlackBerry or TV your final destination of the evening. Using these devices for communication is clearly eating into our sleep time. Texting friends, playing computer games or just watching TV stimulates our brains and bodies, and the extra light we expose ourselves to when we peer at a screen could be throwing off our body clocks.
Questions 19 to 21 are based on the passage you have just heard.
19. Which of the following is helpful for falling asleep according to the passage?
20. What should we do if we cannot sleep according to the passage?
21. Which is the best title for this passage?