How long is the economic distance for motor? （） 750 miles。 1000km。 1000 miles or less。 200 km。
What are the advantages for motor transportation? （） Door-to-door service。 Fast。 Flexibility。 A and C。
Container is most benefit for （） Transport, carrying, loading and unloading。 Storage。 Transporting。 Distribution。
What is the meaning of Metropolitan area? （） Around the city。 City itself。 The area near the city。 Big city and its neighbor area。
Railroads own about （）of their car fleet. Half。 80%。 20%。 Not mentioned。
Crude oil carriers often use （）
