过盈连接的配合面间产生压力,工作时依靠此压力产生()力来传递转矩和()力。
参考答案:摩擦;轴向
24°45′的余角为______°______′.
.—Has your father finished his report?
—Sorry,I don’t know.He ________ it this morning.
A.was writing
B.wrote
C.has written
D.had written