主轴部件是车床的关键部分,在工作时承受很大的切削抗力。
查看答案
A vessel would be referred to as tender when the weight of the cargo is().
A. evenly distrubuted vertically and the double bottoms are full
B. concentrated low and the double bottoms are empty
C. concentrated low and the double bottoms are full
D. concentration high and the double bottoms are empty
在形位公差代号中,基准采用小写拉丁字母标注。
A. 正确
B. 错误
当纵波反射角等于90°时的横波入射角称为第三临界角。
A. 正确
B. 错误