Which of these is most like a closed system that does not allow transfers in or out of the system?
a planet earth
b a coral reef
c a school
d the human heart

Planet Earth  is most like a closed system that does not allow transfers in or out of the system

A. Planet Earth

Explanation:

In a closed system, there is no exchange of mass. However, the energy might get exchanged. The exchange of mass and energy depends upon the property of the membrane or the boundary of the substance or an object.

The Earth is basically a closed framework; it acquires huge amount of energy from the Sun yet the exchange of matter with the outside is just about zero. Material streams between stores or sinks along pathways, or motions.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion