Which type of air pollution was caused by factories during the industrial revolutiona. smoke from burning coalb. soot from forest firesc. smog from high pollen levelsd. smoke from vehicle exhaust

A. smoke from burning coal

Explanation:

coal is a fossil fuel and when burned causes global warming

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

your answer to this question is true hope this