题目：
| 选择方框中适当的选项补全对话（有两项多余） Wu Dong: Hello, Liu Qiang. I have not seen you for several weeks. Liu Qiang: Hi, Wu Dong. Nice to see you again. You didn't sec me these days because I didn't come to school. Wu Dong: Where have you been then? Liu Qiang: 1 Wu Dong: In hospital? What is wrong with you? Liu Qiang: That was an accident. Have you remembered that I said I loved fishing before? Wu Dong: 2 Liu Qiang: Yes. Good memory. I went there fishing three weeks ago. But I fell into the river. Wu Dong: 3 Liu Qiang: I stayed there for about two hours. But I did not catch one fish. So I felt worried. Suddenly I saw a big fish swimming in the river, so I went to catch it with my hands. Wu Dong: 4 Liu Qiang: Then I tell into the river. My left foot was hurt by some glass and I nearly drowned in the river. Wu Dong: Who saved you at last? Liu Qiang: A young man, and he took me to hospital. Wu Dong: 5 Liu Qiang: Yes, thanks. When we do anything, we should keep ourselves safe. Do you agree? Wu Dong: Yes. Safety is the first!
|
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0522/b625b825ad844717eb6810550e83c528.html
下面是错误答案，用来干扰机器的。
电动机效率η的表达式，电动机效率η等于有用功与总功的比值，有用功W=GH，而总功W总=UIt．则有：η=GHUIt 故答案为：GHUIt
