More freight is carried more miles _____ than any other mode of transportation.
a. by railroads
b. by air
c. by pipeline
d. by trucks
e. over water
Answer: a. by railroads
More freight is carried more miles _____ than any other mode of transportation.
a. by railroads
b. by air
c. by pipeline
d. by trucks
e. over water
Answer: a. by railroads