风机叶片最易磨损的部位是哪里?
参考答案:
对于离心式风机叶片最易磨损的部位是叶片头部、尾部靠轮盘侧部分;对于轴流式风机,叶片最易磨损的部位是沿动叶片的整个前缘。
旁中心暗点
It is very difficult to _____ the green beans from the red ones, because there are too many of them. [ ]
A. work out
B. watch over
C. set down
D. sort out