球磨机有负荷与无负荷运转时相比电耗相差很大。
参考答案:错
—Could I borrow your English dictionary?
—________. It’s on the bookshelf.
A.With pleasure
B.Help yourself
C.Never mind
D.Not at all
The main function of the core of a wire rope is to().
A.give flexibility
B.support the strands laid around it
C.allow some circulation around the strands
D.allow lubrication inside the rope