What is the main difference between the use of fossil fuels and the renewable
energy sources?

A)Renewable energy sources can be easily
replenished while fossil fuels cannot.
B) Fossil fuels sources can be easily replenished
while renewable energy sources cannot

the tricuspid valve is present between right atrium and right ventricle

when it is at an intermediate population density

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.