齿轮传动副中,影响传动精度较大的主要是()误差。
A.齿距
B.齿距累积
C.齿圈径向跳动
D.装配
参考答案:B
As a solder, you should defend your country _____ the enemies. [ ]
A. to
B. against
C. in
D. with
乐山大佛是哪个朝代凿刻的?