Which statement describes how the angle of insolation affects different areas of Earth? The area near the pole absorbs more heat.
The area near the equator receives less heat.
The area near the equator is warmer than the area near the pole.
The area near the pole receives more direct sun rays than the area near the equator.

i would say it is

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.