The five primary modes of transportation are rail，road，pipeline，water，and air．Each has dif

The five primary modes of transportation are rail，road，pipeline，water，and air． Each has different economic and service characteristics．【B1】offers the cost—efiective，energy—efficient transport of large quantities of goods over long distances．【B2】offers more flexibility and versatility to the shipper than virtually any other forms of transportation．【B3】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 cost．The most expensive of all the modes，【B4】offers the fast service but at a relative high price．【B5】 occurs on inland waterways and oceans．Though slower than other modes，this form. of movement is also relativelv inexpensive．

【B1】

A．Rail transport

B．Road transport

C．Truck transport

D．Air transport