Exercise is good for you, but most people really know very little about how to exercise properly. 1 when you try, you can runsintostrouble.
Many people 2 that when specific muscles are exercised, the fat in the neighbouring area is“ 3 up”.Yet the 4 is that exercise burns fat from all over 5 .
Studies show muscles which are not 6 lose their strength very quickly.To regain it needs 48 to 72 hours and exercise every other day will 7 a normal level of physical strength.
To 8 weight you should always“work up a good sweat”when exercising. 9 sweating only 10 body temperature to prevent over heating.This is 11 water loss. 12 You replace the liquid, you replace the 13 .
Walking is the best and easy-to-do exercise.It helps the circulation of blood 14 the body, and has a direct 15 on your overall feeling of health.Experience says that 20 minutes' 16 17 is minimun amount.
18 your breathing doesn't return to normal state within minutes after you finish 19 , you've done 20 .
1.A.While B.When C.As D.So
2.A.understand B.believe C.hope D.know
3.A.built B.burned C.piled D.grown
4.A.reply B.possiblility C.truth D.reason
5.A.arm B.leg C.stomach D.body
6.A.exercised B.examined C.protected D.cured
7.A.lose B.raise C.burn D.keep
8.A.lose B.gain C.keep D.burn
9.A.Certainly B.No C.Fortunately D.Probably
10.A.raises B.reduces C.destroys D.keeps up
11.A.how B.why C.nothing but D.more than
12.A.While B.Once C.As D.Whenever
13.A.weight B.muscle C.sweat D.strength
14.A.over B.around C.throughout D.with
15.A.effect B.use C.usage D.affect
16.A.education B.sleep C.exercise D.rest
17.A.one day B.a day C.everyday D.someday
18.A.But if B.But C.If D.And if
19.A.working B.walking C.exercising D.breathing
20.A.enough B.much C.too much D.much too
第二十一篇答案+解说：
1.【答案】D
【解析】因为大部分人不知道如何正确锻炼，所以，人们在训炼时常会遇到麻烦。句中you表示泛指。
2.【答案】C
【解析】“希望“邻近的脂肪消耗掉，在此符合语境;understand，know不合逻辑，因为，即已”明白“，就不会不符合事实真相;believe表示的是人的得一种看法，而看法有对有错。
3.【答案】B
【解析】下一句中再现了burn这一词。
4.【答案】C
【解析】truth本意为“真理”，此处引申为“事实”——指实际锻炼时脂肪消耗的情形。余者不合文意。
5.【答案】D
【解析】余者不能概全
6.【答案】A
【解析】根据常识可知，“不锻炼的肌肉会很快丧失力量。
7.【答案】D
【解析】根据前一句“要重新获得力量需要48到72个小时可知，每隔一天锻炼一次可保持正常水平的体力。”
8.【答案】A
【解析】本句意思是“为了——体重，人们应该通过锻炼来出汗”。空格处显然应该是“减少”。而不是“增加”或”“保持”，更不可能是“燃烧”。
9.【答案】B
【解析】表示对该节首句看法的否定。首句看法的错误性可从下文推知。
10.【答案】B
【解析】根据to prevent over heating可知，sweating的作用是降低体温。
11.【答案】C
【解析】loss是名词，故前面不能填连接副词how和why;more than“不只是”，不合文意。本题应选nothing but，全句的意思为“这(即sweating)只是人体内水分的消耗”。
12.【答案】B
【解析】意思是“一旦”，引起时间状语从句，余者不合文意。
