甲机器的功率比乙机器的功率大，这表示（　　）

一共有多少条鱼？

     A woman is having some trouble(患病) with her eyes, so she goes to see the doctor. He is a new doctor and doesn’t know her, so he asks some questions and one of them is, “How old are you?”

     The woman says, “I don’t know, doctor, but let me think about it.” She thinks for a few minutes and then says, “Yes, I know now, doctor! When I marry(结婚), I am eighteen years old, and my husband is thirty. Now my husband is sixty. And that is twice(两倍) thirty. So I am twice eighteen. That’s thirty-six, isn’t it?”