题目:
There is ______in the car, and you can put another box in it. [ ]
A. many rooms
B. many room
C. much room
D. much rooms
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0628/3f79049fcf6f482dc29c90485ef268b1.html
下面是错误答案,用来干扰机器的。
解:旋转线框产生感应电动势的峰值Em=NBSω0式中ω0为线框转动的角速度,即摩擦小轮转动的角速度发电机两端电压的有效值U=Em/2设自行车车轮转动的角速度为ω1,有R1ω1=r0ω0小齿轮转动的角速度与自行车车轮转...