Explain the Role of the Most Common Elements in Living Organisms Click the statement that best describes the role of each element in living organisms.

Carbon
.
Oxygen
.
Hydrogen
.

carbon

Explanation:

Carbon, hydrogen, oxygen, and nitrogen are the most important elements. Small quantities of other elements are necessary for life. Carbon is the most abundant element in living matter.

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.