The correct answer is: desertification.
Desertification is a process in which a land which was not a desert before, becomes one. This process can include drying out- through for example loss of water source, such as river diversion- and the loss of vegetation.
The correct answer that would best complete the given statement above would be CELL RESPIRATION and FOSSIL FUELS. Carbon dioxide enters the atmosphere by animal and human cell respiration and the burning of fossil fuels. Human activities such as BURNING FOSSIL FUELS and RESPIRATION cycle carbon through the carbon cycle. Hope this is the answer that you are looking for.
Answer:
1st graph/diagram --> 2nd description (between top and bottom)
2nd graph/diagram --> 3rd description (bottom/last one)
3rd graph/diagram --> 1st description (top one)
They transport oxygen to all the cells of the body
