A、It exhausts you physically. B、It makes you fall asleep easily. C、It causes you to lose body heat. D、It consumes too much oxyge

Good transportation is very important in winter. If you have a car, make sure it is ready for the cold weather. Keep the gas tank as nearly full as you can. This will keep water out of the tank and will be a reserve in case you get into trouble. If a storm traps you in your car, there are some steps you should take for your own safety. Do not attempt to walk to find help. You may quickly lose your way in blowing and drifting snow. Your chances of being found are better if you stay in your car. Keep a downwind window open slightly for fresh air. Freezing rain can seal off your car and lock you inside. Run the engine and heater once in a while. Keep the same downwind window open while the engine is ninning. Make sure that snow has not blocked the exhaust pipe. Clap your hands and move your arms and legs from time to time. Do not stay in one position too long. But, do not move too much. Exercise warms you up, but it also causes you to lose body heat. If more than one person is in the car, do not sleep at the same time. One person should always be awake. If you are alone, stay awake as long as you can. Turn on the inside light at night. This will make your car more visible to rescue crews. Don’t panic. Stay with your car.
16. What does the speaker say you should do in winter with your car?
17. What should you avoid doing if a storm traps you in the car?
18. Why is too much exercise undesirable when you are trapped in a car by a winter storm?