Explanation:
Two important ways by which humans have affected the carbon cycle, especially in recent history, are: 1) the release of carbon dioxide into the atmosphere during the burning of fossil fuels, and 2) the clearing of trees and other plants (deforestation) that absorb carbon dioxide from the atmosphere
Answer:
The return of blood to the heart is assisted by the action of the skeletal- muscle pump. As muscles move, they squeeze the veins running through them. Veins contain a series of one-way valves, and they are squeezed, blood is pushed through the valves, which then close to prevent backflow.
Answer:
9 th qn answer us 4th option(D)
and 10 th qn answer is 3rd option (C)
Answer:
Antibiotics are strong medicines that treat bacterial infections. Antibiotics won't treat viral infections because they can't kill viruses.
Explanation:
You'll get better when the viral infection has run its course. Common illnesses caused by bacteria are urinary tract infections, strep throat, and some pneumonia.
