A change or a slight difference
The answer is concrete laundry trays.
This is because as concrete trays ages with timeit becomes coarse and rugged due to water, soap and detergents. Their smoothness gradually fades with time, thus this makes it not as good regarding to health wise standards of living.
Answer:
creation of a burning chamber which will suppress the chemicals released into a usable form.
Explanation:
hope it helps .
