筛分过程的技术经济指标是()
A、筛分效率
B、筛分效率与生产率
C、生产率
D、总效率
参考答案:B
On April 10, 2010, the Polish presidential plane did not ________ to the runway while landing. It hit the treetops and fell apart.
A.take it
B.make it
C.get it
D.put it
辊式矫直机的辊数增加有利于提高矫直精度。