阅读理解。 Hi, there! I’m Crystal Collins, and I’m very happy to share some time with you. So, you want to keep fit, huh? Well, you surely came to the right place. Together we can keep fit and healthy, and succeed in doing that. It’s easy. Everybody can do it, you hear? Just remember the five golden rules. Number one. Always wear comfortable clothes when you are exercising. You need to feel comfortable and relaxed. Number two. You should always do some warming-up exercises first. Get your body ready for the real thing. Number three. Never try to do too much exercise too soon. T ake it nice and easy now, you hear? There’s no rush about this. Number four. Don’t forget to relax for about five minutes when you’ve finished your exercise. You need to rest a little bit after you’ve been exercising. And here is golden rule number five. Stop at once if you feel any pain in your neck, head or any part of your body. 1. Crystal Collins may most probably be _____. A. a teacher B. a doctor C. a policeman D. a scientist 2. Crystal Collins may most probably say this _____. A. before the exercise starts B. when the exercise is over C. during the exercise D. as soon as the exercise has started 3. What does the underlined words “Take it nice and easy” in Paragraph 4 mean? A. Don’t be nervous.B. Exercise should be beautiful. C. Have a good rest.D. don't exercise too tiredly . 4. Which of the following is NOT true about exercising? A. You should do some warming-up exercises before the real thing. B. You should wear comfortable clothes. C. You should rest for a while when you are doing warming-up exercises. D. You should stop if you feel any pain in your body.