提高机械效率的途径有:尽量简化机械传动系统、选择合适的运动副形式、尽量减少构件尺寸、减少摩擦。()
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The FIFA admits officially that football originates in China.
A. 对
B. 错
Cuju is one of the Britishtraditional sports.
A. 对
B. 错
Qiyun Associationwas a spontaneous organization by the folk players.
A. 对
B. 错
“Cu” means to kick, and “Ju” is a kind of ball in ancient China made of stone.
A. 对
B. 错