塑性材料制成的零件进行静强度计算时,其极限应力为()
查看答案
自行车后轮轴属于()。
A. 心轴
B. 转轴
C. 传动轴
D. 曲轴
某三相异步电动机的额定频率为50Hz,额定转速为980转/分,则此电动机的磁极数为()。
A. 不能确定
B. 6
C. 3
D. 3.06
Complete the sentence with one of three words .They climbed over the mountain ______.
A. safe
B. safely
C. safety
Kim felt _______ when he finished the project.
A. tiredness
B. tiredly
C. tired