"A. cutting down most of the trees in a forest to make furniture" is the correct answer because some trees play a vital role in processing the carbon in the air.
A. The onset of the menstrual flow
The correct answer is Protozoans.
Protozoans are best described as uni-celled eukaryotic organisms, both free-residing or parasitic, which feed on organic matter together with different microorganisms or organic tissues and particles. back then, the protozoa have been seemed as "one-celled animals," because they regularly possess animal-like behaviors, together with motility and predation, and lack a mobile wall, as discovered in plant life and plenty of algae.
Answer:
Lungs supply oxygen carried by blood to cells of the body. The cells which are responsible for the transportation of oxygen is hemoglobin. When oxygen rich hemoglobin reaches a cell so the oxygen is unloaded and carbondioxide which is produced as a waste product is loaded in hemoglobin. Again this hemoglobin goes to the lungs and dispose carbondioxide there and repeat the process again.