听力原文： Do you have trouble sleeping at night? Then maybe this is for you. When you worry about needing sleep and toss and turn trying to find a comfortable position, you're probably only making matters worse. What happens when you do that is that your heart rate actually increases, making it more difficult to relax. You may also have some bad habits that contribute to the problem. Do you rest frequently during the day? Do you get virtually no exercise, or do you exercise strenuously late in the day? Are you preoccupied with sleep? Or do you sleep late on weekends? Any or all of these factors might be leading to your insomnia by disrupting your body's natural rhythm. What should you do then, on those sleepless nights? Don't bother with sleeping pills. They can actually cause worse insomnia later. The best thing to do is drink milk, or cat cheese or tuna fish. These are all rich in amino acids and help produce a neurotransmitter in the brain that induces sleep. This neurotransmitter will help you relax, and you'll be on your way to getting a good night's sleep. Until tomorrow's broadcast, this has been another in the series 'Hints for Good Health.' (33)