Question

During the late 1800s, pollution in cities was caused partly by horses, coal, and inadequate sewer systems. true or false ?

Answer 1

I'd likely pick "true" in this case.

In the late 1800s, horses were still used for everyday transport. And horses pretty much went wherever they wanted if it was a paved, cobblestone street or a dirt path. To provide heat in homes and steam power in factories, coal was also used as a cheap fuel by everyone. So as a result, you have chimneys belching smoke everywhere. This was before there ever were safety standards for coal burning other than the the usual "don't stand too close to the boiler/furnace" or "watch out for coal dust" warnings. Factories set up close to or inside cities that burned tons of coal wasn't an unusual thing back then.