Unit 57 Be on the lookout for substitutes

　　Unit 57 探索各式各样的食品

　　Every day is a day of discovery.Yesterday,you found out that frozen yogurt tastes as good as ice cream but with a lot fewer calories,Today,you put mustard on your sandwich instead of mayonnaise and saved 30 calories.And tomorrow... who knows?

　　每天都可以有新发现，昨天你发现冷冻的酸奶味道和冰淇淋一样好.不过它的卡里路却少很多。今天，你不在三明治上涂蛋黄酱而改涂芥末酱，因而少吃了三十卡路里的热量。而明天的新发现……，谁晓得呢?

　　Keep your antenna out for the thousand-and-one small but significant substitutions you can make.Read product labels.Pay attention to ads and commercials.Ask friends and family.You'll be an expert before you know it.

　　随时伸出触角.探索各式各样小兵立大功的饮食替代方式仔细阅读各种食品上的标签。注意广告和宣传。请教朋友和家人。不知不觉中，你就会成为专家了。

　　健身短语

　　1.be on the lookout f'or...留意……

　　2.…before sb knows it 不知不觉中，某人就....