单项选择题
Which area is the most commodities shipped in water transport?（）
A. In international deep sea B. In lakes C. In river and canals D. Coastal ocean
单项选择题 What is the meaning “speed is not of primary importance”? （）
单项选择题 What are transported mainly by water? （）
单项选择题 How many categories are there in water transport?（）
