The thick rock layer around the earth’s is the mantle.
a. crustc. atmosphereb. cored. faults

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

digestion

it excretes wastes