People who eat a balanced diet should behealthier than those who only eat biscuts and hamburgers,shouldn't they?中有几个从句啊?都是什么从句呢?

两个从句.
People who eat a balanced diet should be healthier than those who only eat biscuts and hamburgers， shouldn't they?
第一句是 who eat a balanced diet,修饰poeple, 意思是饮食均衡的人.
第二句是 who only eat biscuts and hamburgers，意思是只吃饼干和汉堡包的人.
整句话意思是饮食均衡的人应该比只吃饼干和汉堡的人更健康,不是吗?
可以把它化简一下,句子的主干是" People ...should be healthier than those..., shouldn't they?" (....r的人应该比....的人更健康,不是吗?)

People who eat a balanced diet should be healthier than those who only eat biscuts and hamburgers，______?
A,don't they B. do they C. shouldn't they D. should they ?
此题为杭州2012 中考题，答案是C,仔细探讨此题，如果要求作出回答，是否该回答成，Yes,they do. 还是Yes, they should.

People who eat a balanced diet should be healthier than those who only eat biscuts and hamburgers,shouldn't they?who eat a balanced diet这是定语从句修饰peoplewho only eat biscuts and hamburgers这也是...