[解析]
(1)B 细节理解题。根据Eating too much can make you feel uncomfortable.If you do it to often,it can make you unhealthy and fat.吃得太多会使你感到不舒服。如果你经常这样做,会使你不健康和肥胖。可知,吃得太多会让你增重。故选B。
(2)A 细节理解题。根据We should do exercise for at least 140 minutes every week according to the World Health Organization.根据世界卫生组织的说法,我们每周至少应该锻炼140分钟。所以每天应该锻炼140÷7=20分钟,故选A。
(3)B 主旨大意题。通读全文且结合Tell your parents and friends about these rules.Let them have a healthy life.告诉你的父母和朋友这些规则,让他们有一个健康的生活。可知,本文主要介绍了保持健康的方法。故选B。