如图所示，刀具起点在（-40，-20），从切向切入到（-20，0）点，铣一个40mm的整圆工件，并切向切出，然后到达（-40，20）点。根据示图中的刀具轨迹判断，正确的程序是（）。 ["A．……","N010G90G00G41X-20．0Y-20．0D01；","N020G01X-20．0Y0F200．0；","N030G02X-20．0Y0I20．0J0；","N040G01X-20．0Y20；","N050G00G40X-40．0Y20．0","……","B．……","N010G90G00G41X-20．0Y-20．0D01；","N020G01X-20．0Y0D01F200．0；","N030G02X-20．0Y0I-20．0J0；","N040G01X-20．0Y20；","N050G00G40X-40．0Y20．0","……","C．……","N010G90G00X-20．0Y-20；","N020G01X-20．0Y0F200．0；","N030G02X-20．0Y0I-20．0J0；","N040G01X-20．0Y20；","N005G01G00X-20．0Y20．0","……","D．……","N010G90G00X-20．0Y-20．0；","N020G91G01G41X20．0Y0D01F200．0；","N030G02X-20．0Y0I20．0J0；","N040G01X-20．0Y20．0；","N040G01X-20．0Y20．0；","……"]
下列牌号中，属于工具钢的是（）。 ["A、20","B、65Mn","C、T10A"]
交叉杆安全链链环直径磨耗大于（）时更换。 ["A、lmm","B、2mm","C、3mm","D、5mm"]
水库端与完全关闭的阀门端对水锤波的反射特性分别为（）和（）。
六经
鸿都门学
