许多美国人都为自己体重超重而担忧 - Americans are constantly worrying about extra pounds. 他们想尽办法来减肥--They try all means to shed their extra pounds。很多人通过跑步，锻炼来减肥 - try to get rid of their extra pounds by running and exercising.可是饱餐一顿往往会全功尽弃，甚至再加上一，两磅 - a big meal might add a couple of extra pounds! 今天学的一个词组是extra pounds...