单项选择题
What is the most important market-related factor to the transport cost? （）
A. Location of market B. Government regulation C. competition D. Seasonality of products flow
单项选择题 What is the most important product-related factor the transport cost? （）
单项选择题 How many product-related factors are there to influence the transport cost? （）
单项选择题 Which mode of transportation is most flexible? （）
