The answer to that is biosphere
~The images below will hopefully help. :)
*The pulley is a lever, and it helps lifts things higher with less force then trying to normally pick it up.
Answer:
Human activity is the main cause of climate change. People burn fossil fuels and convert land from forests to agriculture. Since the beginning of the Industrial Revolution, people have burned more and more fossil fuels and changed vast areas of land from forests to farmland.
Explanation:
Cardiovascular muscle is the answer