客源管理是从搜集信息、整理信息和( )开始的。
A.分析信息 B.应用信息 C.反馈信息 D.存档
参考答案:D
It was with great delight that I read in your February _____ the letter to the Editor written by Prof. Johnson.
A.issue
B.printing
C.magazine
D.copy
JZ-7型空气制动机单独制动阀在全制动位时,制动缸压力自0升到280kPa的时间为()。
A、1~2s
B、2~3s
C、4s
D、4~5s