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 it’s 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 won’t 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 flushing and painting rusty bridges consume a large part of a city’s budget.
b. salt and rust are corrosives that have damaging effects on a city’s infrastructure.
c. salt is the most damaging compound that people can use to fight snow and ice.
d. salt can be used as a metaphor for a monster that has a voracious appetite.

B. Salt and rust are corrosives that have damaging effects on a city’s infrastructure.

Explanation: in a text, a main idea is important information that tells more about the overall idea of a paragraph or section of a text. In the given excerpt from "The City Without Us” by Alan Weisman we can see the description of how the salt used on the roadways on winter, is very corrosive because it eats steel, and it also says that with no people, there won't be salt, but there will be rust which is also corrosive. According to this information, the main idea of the paragraph is best represented by option B: Salt and rust are corrosives that have damaging effects on a city’s infrastructure.

i would think its c but i'm not sure

the bazaar because it represents the inaccessible land of freedom to the narrator. mangan’s sister because she represents domesticity and routine to the narrator. the marketplace because it represents the suburban lifestyle to the narrator. the church because it represents spiritual healing and renewal to the narrator.