20．Having an exercise plan is important，but you should always ask your doctor for advice before starting it．Keep in mind that you can have too much of a good thing：overexercising and exercising in a wrong way can hurt your body．The following suggestions can help you avoid（避免） this． Warm up before exercise．This helps to prepare your body for activities．It's especially important in the morning． Cool down after exercise．Rather than stop immediately，do a few light activities to avoid aches and pains later． Exercise with your limits（极限）．Build up slowly．Never try to exercise when you feel painful．If you don't listen to your body，you will hurt yourself． Avoid being thirsty．Water is important to keep your normal temperature during exercise and prevent（预防） tiredness． Wear sports shoes．These shoes can keep your feet safe and prevent you from being hurt． 66．The writer gives usC suggestions in the passage． A．three B．four C．five D．six 67．Before you start your exercise plan，you shouldB． A．make up these suggestions B．ask your doctor for advice C．find your health problems D．have a careful health exam 68．A is especially important before exercise in the morning． A．Warming up our body B．Cooling our body down C．Drinking enough water D．Putting on sports shoes 69．The third suggestion can help us toD． A．prepare for our activities B．avoid aches or pains later C．keep normal temperature D．avoid hurting ourselves 70．This passage mainly tells usC． A．to warm up before exercise B．how to keep healthy C．how to exercise in a right way D．not to exercise too much．
