题目内容：
根据下列选项，回答题。Transportation is one of the most significant areas of1 lbecause of its impact on customer service and the firm’s cost structure．The primary transportation value proposition is product movement up and down the supply chair．Without reliable transportation， most commercial activities could not function．The international 2is nowadays frequently carried out in containers．Containers are particularly suitable for3． If the exporter intends to fill a full container load，the forwarder or shipping line will prepare an empty container to the exporter for loading．If the cargo is 4， the exporter sends it to the container freight station，where it will be 5with the goods of other exporters in a container．
请在1处填上正确答案
参考答案：
答案解析：