Some people say that the best way to reduce the size of your waist is to do stomach exercise. Many people believe that when specific muscles are exercised, the fatty tissues   in the immediate area are burned up. The truth is that exercise burns fat from all over the body and not from one specific area. Of course, if you reduce the fat throughout your body, you will certainly see results around your waist too. Some people believe that you need to exercise twice a week in order to keep a sufficient level of physical fitness. However, studies directed by American scientists show that unexercised muscles lose their strength very quickly. Within 48 to 72 hours, you must use the muscles again to reestablish   the good physical effects. And what does that mean to you? American scientists concluded that while daily exercise is most helpful, exercising every other day or three days a week will keep a sufficient level of physical fitness. Is it true that you burn more calories running one mile than walking the same distance? The answer is no. The truth is that you use the same amount of energy whether you walk or run the mile, since in both cases you are moving the same weight the same distance. The speed does not matter. Of course, if you run rather than walk for 30 minutes, you will cover more distance, and therefore burn more calories. If your breathing doesn't return to normal within 5 minutes after you finish exercising, you have exercised too much. Five minutes or so after exercising, your breathing should be normal, your heart shouldn't be beating loudly, and you shouldn't be tired. This passage tells us that   _  .
it is better to do more running than walking the more exercise you do, the healthier you will be the unexercised muscles must be used again within 48 to 72 hours in order to lose weight, you have to run fast
Question: Some people say that the best way to reduce the size of your waist is to do stomach exercise. Many people believe that when specific muscles are exercised, the fatty tissues   in the immediate area are burned up. The truth is that exercise burns fat from all over the body and not from one specific area. Of course, if you reduce the fat throughout your body, you will certainly see results around your waist too. Some people believe that you need to exercise twice a week in order to keep a sufficient level of physical fitness. However, studies directed by American scientists show that unexercised muscles lose their strength very quickly. Within 48 to 72 hours, you must use the muscles again to reestablish   the good physical effects. And what does that mean to you? American scientists concluded that while daily exercise is most helpful, exercising every other day or three days a week will keep a sufficient level of physical fitness. Is it true that you burn more calories running one mile than walking the same distance? The answer is no. The truth is that you use the same amount of energy whether you walk or run the mile, since in both cases you are moving the same weight the same distance. The speed does not matter. Of course, if you run rather than walk for 30 minutes, you will cover more distance, and therefore burn more calories. If your breathing doesn't return to normal within 5 minutes after you finish exercising, you have exercised too much. Five minutes or so after exercising, your breathing should be normal, your heart shouldn't be beating loudly, and you shouldn't be tired. This passage tells us that   _  .
A. it is better to do more running than walking
B. the more exercise you do, the healthier you will be
C. the unexercised muscles must be used again within 48 to 72 hours
D. in order to lose weight, you have to run fast
Answer: