It causes pollution
It can cause loss of life
True, though the Hadean period is one exception.
Alveoli are part of the reparation system found in the lungs. They are covered in capillaries. In Alveoli, oxygen diffuses from the air into the blood vessels surrounding the alveoli and carbon dioxide from the body diffuses from blood into the alveoli’s air spaces. Alveoli clump together and form sacs.
Answer:
In animals that give live birth, the fetal circulation is the circulatory system of a fetus. The term usually encompasses the entire fetoplacental circulation, which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood.
Yes it is C but for future reference, both A and B are referring to solids, and D is referring to a gas, hope this is helpful later!