Cloze 1 请填写完整单词 Railroads carry an important part of the total f______. The a_________ of rail transport lies in its a_______ to meet different needs. Railroads can carry the heaviest and the lightest p________ and can run at different speeds. For s________ types of goods railroads provide a________ cars. Thus for p_______ refrigerator cars are used, for oil products there are tank cars, for different other m_________ dumper cars are used. The freight rates of railroads compare f________ with the other modes of transport.