Question

building the transcontinental railroad across the united states required vast amounts of manpower, resources, and planning. it is regarded as one of the greatest achievements in u.s. history. its construction could be compared to the digging of the panama canal and the landing of men on the moon. this railroad allowed the u.s. to grow more easily, in size and population, from the atlantic ocean to the pacific ocean.
the u.s. grew quickly during the middle of the 19th century. much of this growth was east of the mississippi river. many politicians and businessmen from the u.s. wanted to push west and connect the atlantic and pacific coasts. at the time, the steam locomotive was the best choice for this task. however, laying railroad tracks was a time - consuming effort. the process included preparing the track ballast, or trackbed.
this was a layer of crushed stone where the railroad ties and rails sat. the crushed stone allowed for better water drainage. it also prevented vegetation from growing around the track. the ties were wooden planks that rested on the trackbed. the rails were made of metal and were connected to each tie with metal spikes. this process made the transcontinental railroad a difficult operation.
construction began in 1863, during the civil
13
based on the context of the passage, the track ballast is the
a. part of the train engine that increases speed
b. section of the locomotive that releases steam
c. place where the railroad rests on the ground
d. worker who fixes any loose spikes, rails, or ties

Explanation:

The passage states that track ballast is "a layer of crushed stone where the railroad ties and rails sat" that aids drainage and stops vegetation growth, which matches the description of the ground/bed area for the railroad. The other options do not align: A and B refer to locomotive parts, and D refers to a worker, none of which match the definition given.

Answer:

C. place where the railroad rests on the ground