下图反映了我国古代不同封建王朝官员上朝的礼仪，实际上代表了君臣关系的变化。其反映 的实质问题是（    ）

    Most English people have three names: a first name, a middle name and a family name. For example, my full name is Ann Allan Green. Green is my family name. Ann and Allan are my given names. People don't use their middle names very much.So we can say Ann Green. We can say Miss Green or Mrs. Green. But we can't say Miss Ann or Mrs. Ann. It's different from Chinese names. In China, the first name is the family name and the last name is the given name.

一只鲸鱼一天吃2吨小虾，5天能吃多少吨虾？