单项选择题
What is the meaning of integration? （）
A. To link some separate factors as a whole chain B. United C. To put together D. Mixture
单项选择题 How many flows are there in global logistics?（）
单项选择题 How long the haul for international deep-sea movement usually? （）
单项选择题 Which area is the most commodities shipped in water transport?（）
