客户是流动的,不断变化的,这造成了客服工作的()。
A、对象不统一性
B、不可度量性
C、不可重复性
D、不可贮存性
参考答案:D
一条直线长20米。 [ ]
Those boys didn't start the work _____ their teacher come back. [ ]
A. until
B. while
C. as soon as
D. if