Describe two factors that cause variations in climate?

Solar activity (sunspots) and geologic activity (volcano's/earthquakes). These are the two major factors that probably produce more than 99% of climate variation. There are probably several hundred contributing factors working along with these two major ones of which Co2 is the least contributing to them all.

The answer is a. i hope this

Answer : romans built laws to manage the pollution which was lead by smoke produced by the factories.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.