Exercise is one of the few factors with a positive role in long　term maintenance of body weight. Unfortunately, that message has　not gotten through to the average American, that would rather tr ...

Exercise is one of the few factors with a positive role in long　term maintenance of body weight. Unfortunately, that message has　not gotten through to the average American, that would rather try __1__ switching to "light" beer and low-calorie bread than increase physical　exertion. The Centers for Disease Control, for example, found　that fewer than one-fourth of overweight adults were trying to shed __2__ pounds said they were combining exercise with their diet.

In rejecting exercise, some people may be discouraged too　much by calorie-expending charts; for example, one would have to __3__ briskly walk three miles just to work the 275 calories in one __4__ delicious Danish pastry. Even exercise professionals concede half a　point here. "Exercise in itself is a very tough way to lose weight," __5__ says York Onnen, the program director of the President's Council on __6__ Physical Fitness and Sports.

Therefore, exercise's supporting role in weight reduction is vital. __7__ A study at the Boston University Medical Center of overweight police　officers and other public employees confirmed that those who diet __8__ without exercise regained almost all their old weight, while those　who worked exercise into their daily routine maintained their new weight.

If you decide to start walking one mile a day, the added exercise　could burn an extra 100 calories daily. In a year's time, assumed no __9__ increase in food takein, you could lose ten pounds. By increasing the __10__ distance of your walks gradually and making other dietary adjustments,you may lose even more weight.　　

答案：

1.that--who．that从句修饰的是the average American，而且它是一个非限定性定语从句，而that无法引导一个非限定性定语从句，所以应把that改为who。

2.adults^--who．found后接的从句中主要的动词应该是said，而不是try to shed pounds，所以应该在were前面加上who构成定语从句修饰overweight adults。

3.expending--expenditure．由于caloric是形容词，表示属于或者关于卡的，它后面不能接动词的-ing形式，而且expending和charts的关系也不成立，所以应该改为名词expenditure。

4.work^--off．work off有消耗之意，符合文义。

5.in--by(直接把in 去掉也可以吧？)．in itself 表示本身，本质上，而我们都知道锻炼是一减肥的好方法，只是不能仅靠锻炼，还需配之以适当的饮食控制，所以应该把in itself换成by itself，表示单独。

6.the(program)--/．在用作同位语表示独一无二的职位的名词之前，通常用零冠词。

7.Therefore--Still/Neverthless．根据上下文，这里要表达的关系是让步，不是因果。

8.diet--dieted．这里叙述的是过去的一项研究。

9.assumed--assuming．assume和you的关系应是主动的，所以应改为assuming。

10.takein--intake．take in 表示摄入，吸收，它的名词形式不是take in，而是 intake。