Passive solar heating is a technique where the sun's energy
is used for heating spaces. It does not generate electricity but can save substantial
electricity by making use of thermal mass. Materials that have a high density
such as concrete and bricks absorb and store electricity. Along with operable windows
and thermal chimneys, thermal mass is being
utilized to take advantage of sun exposure.
Answer:Christianity became very popular in the ancient world for a number of reasons. When Christianity entered the ancient world, the Romans accepted it,
