题目内容：
根据下列选项，回答题。The five primary modes of transportation are rail，road，pipeline，water and air．Each
has different economic and service characteristics．2 0ffers the cost—effective，energy— efficient transport of large quantities of goods over long distances．1 0ffers more flexibility and versatility to the shipper than virtually any other forms of transportation．3 are primarily used to move petroleum，natural gas，and chemicals．For suitable commodities，pipelines are the most efficient mode of transport．They offer a closed system with little risk of loss or damage to the products moved and extremely low Costs．The most expensive of all the modes，4 0ffers the fast service but at a relative high price． 5 0ccurs on inland waterways and oceans．Though slower than other modes，this form of movement is also relatively inexpensive．
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