1. E
结合上文所说的他在吃什么,可推测本空会说他在吃的东西。故选E
2. D
结合后句I'll go to tell him about it. (我去告诉他这件事。) 可知,这里提到了某事。结合上句提到的弟弟在吃糖果和蛋糕,可推测这里会说吃甜食对牙齿不好。故选D
3. A
结合答语I know, I know.(我知道,我知道。)可知,本句为劝弟弟不要吃太多甜食。故选A
4. C
根据后句It can help you clean your teeth. (它可以帮助你清洁牙齿。)可知,本处提到了吃甜食后喝点水。故选C
5. B
根据后句They're good for your health too. (它们对你的健康也有好处。)可知本句提到了对健康有好处的食物。故选B