Answer: A
Explanation: Vaccines create memory cells with a weak version of the pathogen, so when they meet that pathogen again the body can respond more quickly and more efficiently since they have already been exposed to the pathogen.
I'm guessing changing gravity
I'm pretty sure the answer is B have a nice day
THIS IS known as the PERICARDIUm
Answer:
B
Explanation:
As the moon rotates around the Earth the angle of light given off from the sun changes.
