Question

question 5 of 20
read this excerpt from \the city without us\ by alan weisman:

enemy number one is the salt that highway departments
spread on the roadways each winter—ravenous stuff that
keeps eating steel once its done with the ice. oil,
antifreeze, and snowmelt dripping from cars wash salt into
catch basins and crevices where maintenance crews must
find and flush it. with no more people, there wont be salt.
there will, however, be rust, and quite a bit of it, when no
one is painting the bridges.

which sentence best states the main idea of this section of the chapter?

a. salt is the most damaging compound that people can use to fight
snow and ice.

b. salt can be used as a metaphor for a monster that has a
voracious appetite.

c. salt flushing and painting rusty bridges consume a large part of a
city’s budget.

Explanation:

The excerpt identifies salt as "enemy number one" for its damage to steel, notes it’s spread to fight ice, and contrasts human-maintained salt use with post-human rust. Option A aligns with the main focus on salt’s damaging nature in snow/ice control. Options B (metaphor) and C (budget) are not addressed in the text.

Answer:

A. Salt is the most damaging compound that people can use to fight snow and ice.