货位编号的目的是______。
A．提高作业效率
B．最大限度利用仓库有效的空间
C．防止出现差错
D．商品储存安全
E．库房整齐
参考答案：A,C
The young pioneers kept on working in the fields ________ they felt tired and thirsty.[ ]
A. but
B. or
C. even though
D. since
工程塑料管
