What system breaks down food and what system transports nutrients to the cells of the body?

What do scientific models predict will happen to earth's temperature if current trends continue unmitigated? a. earth will heat and cool in a natural cycle b. earth will heat up and then return to an ice age c. earth will continue to warm at a rate of 0.25 c per decade d. earth will start to cool at a rate of 0.25 c per decade appex