物流科学是在生产发展到一定水平之后，适应社会经济的需要才产生的，这是形成物流后进性的根本原因。
参考答案：对
The shop assistants there were not friendly to me because of ____ .
A．I was badly dressed
B．the clothes I was having on
C．what I was wearing
D．what I dressed
四色法图像有多少通道？（）
A.1
B.2
C.3
D.4
