重点讲解：
1. lose weight
体重减轻；变瘦；
eg. She has been taking exercises to lose weight from day to day.
她每天锻炼来减肥。
eg. Several ladies who were trying to lose weight had already fallen by the wayside by eating cream cakes.
几位女士试图减肥，但同时又吃奶油蛋糕，结果是半途而废。
2. work out
锻炼；健身；
eg. I work out regularly to keep fit.
我经常做运动以保持健康。
eg. The basketball players are working out at the gym.
篮球运动员们正在体育馆进行训练。
3. common sense
常识；直觉判断力；
eg. He behaves as if he had no common sense.
他的言行就好像没有常识似的。
eg. Knowledge without common sense count for little.
没有常识的知识没多大用处。
4. for sure
无疑；肯定；
eg. I know for sure that the chances are in favor of those who are always ready.
我确实相信,机会属于时刻准备着的人。
eg. I think he'll be back on Monday, but I can't say for sure.
我想他星期一会回来，不过我不敢肯定。
