步进电动机的______是指它在一定的负载转矩下能够不失步地启动的最高频率。
下列不属于效率比率的是（）。
A. 应收账款回收期
B. 存货持有天数
C. 负债与所有者权益比率
D. 固定资产周转率
编制用刀具位置偏置指令铣削如下图所示零件外轮廓的加工程序。刀具直径为φ20mm，偏置号为H01，偏置量为+10.0mm。加工路线从O点开始，经过A、B、C、D、E、F、G、H、H’、I’、I、J、A点，又回到O点。
A.Because they don’t think foxes are harmful．B.Because they think fox hunting is
A. Because they don’t think foxes are harmful．
Because they think fox hunting is cruel．
C. Because they think fox hunting is expensive．
D. Because they think the number of foxes has dropped a lot．
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