The answer is a low-density particle
Humidity. I think you need to work on your grammar a little bit pal, if you ever need help with ELA homework, hmu.
Due to the need to have completely controlled experiments to test a hypothesis, science can not prove everything. For example, the scientific method cannot alone say that global warming is bad or harmful to the world, as it can only study the objective causes and consequences.
Decreased blood flow due to limiting the amount of blood
your answer will 100% be C.