All elements are made of "atoms", and an atom is made up from 3 basic particles: Electrons are particles with a negative charge :)
The answer is B) Genetic variation
I don't think we can say for sure. The crystal clear odor free water is probably safest to drink, but it could have some sort of poison mixed in it. And the semi cloudy green water is probably bad to drink, but it could just be vegetables making the water look green and cloudy.
Phospholipid makes the plasma membrane of cells
Answer:
because viruses adapt and change over time. so by the time they come up with something that might help, the virus would most likely be different and harder for the vaccine to work
Explanation:
