已知（1+ax）5=1+10x+a2x2+bx3+…+anxn，则a2=____ 发布时间：2017-05-16 21:29 │ 来源：www.tikuol.com 题型：填空题 问题： 已知（1+ax）5=1+10x+a2x2+bx3+…+anxn，则a2=______．
题型：填空题 情景交际(有两项为多余项)。A: When did you first go swimming? B: When I was 5 years old. A: 1 B: I felt very nervous and frightened. A: Me, too. I went swimming with my elder brother for the first time. 2 So I cried to go home as soon as we arrived at the swimming pool. What happened to you next?B: 3 Then he began teaching me how to swim in the water near the beach. A: 4 B: No. It was rather hard. 5 A: And now you are the best swimmer in our class. B: Yeah. I'll practice harder in the future.A. But because of my father, I swim better and better.B. Was it easy to learn to swim? C. My father asked me to be brave. D. After that I felt very tired. E. How did you feel then?F. Swimming is my favorite sport. G. I was afraid of water. 查看答案