按JB4248-86标准,对于大型锻件进行纵向磁化时,磁化电流应在()安匝的范围内
参考答案:1200-4500
About 5,000 cars _____ in the factory last month. [ ]
A. have produced
B. were produced
C. was produced
D. will be produced
DF4型内燃机车牵引区段的中间站到发线有效长850m,以14.3m为换算单位计算,其股道容车数为()。