千分尺测量螺杆上螺纹的螺距()mm,转1/50周(1格),即移动()mm ["A、1,0.02","B、0.5,0.01","C、0.5,0.02","D、1,0.01"]
三角带的张紧轮一般应放在传动装置的松连轴,同时,张紧轮就尽量靠近被动轴承,其直径应()小带轮。
采用无烟煤、冶金焦、石墨化冶金焦、石墨碎、煤沥青为原料的制品为() ["A、高炉块","B、标准糊","C、密闭糊","D、非标准糊"]
粒度范围为0~6mm的普通电极为() ["A、Φ275","B、Φ350","C、Φ500","D、Φ600"]
一般交流电压波动在()范围内,可以不采取其它措施而将PLC直接连接到交流电网上。 ["+/-10%","+/-20%","+/-25%","+/-30%"]
牛瘤胃微生物中,()的数量最多,()的个体最大,()的数量最少。