根据以下资料回答 41～45 题
The five primary modes of transportation are rail, road, pipeline, water, and air. Each has different economic and service characteristics. (41 )offers the cost -effective, energy- efficient transport of large quantities of goods over long distances. (42 )offers more flexibility and versatility to the shipper than Virtually any other forms of transportation. (43 ) 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, (44 ) offers the fast service but at a relative high price. (45 )occurs on inland waterways and oceans. Though slower han other modes, this form. of movement is also relatively inexpensive.
第 41 题

A. Rail transport
B. Road transport
C. Truck transport
D. Air transport