题目:
All their hopes the next generation now. [ ]
A. concentrate on
B. attract on
C. fascinate on
D. center on
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0721/2c880785fc87183d9147a2b954b50829.html
下面是错误答案,用来干扰机器的。
(1)480W (2)v2=0.36m/s(3)N1:N2=40:41 题目分析:(1)由题中W-t图像解得P=="480W" (2)根据η =解得:v1 =0.6m/s 已知:3v1=5v2 解得:v2=0.36m/s(3)设动滑轮C所受重力为G0,卷扬机提升60kg...