You should consider how much you want to make, so make a budget. See if the equipment is good quality.
Answer:
The answer is Spanish flu
1. natural selection acts on existing traits because you can not evolve into something you didn't have
2. original structures evolve to accomplish new function in order to survive
B is correct. Krypton is a noble gas which has a full outer shell of 8 electrons and is generally unreactive because of it.
The correct answer is D, white blood cells.
We know that red blood cells deliver nutrients and are not apart of the immune system; platelets are responsible for coagulation, which has nothing to do with the immune system, and plasma is a substance that, again, has nothing to do with immunity. White blood cells are the only things that fight disease (antibodies are white blood cells)!
I hope I helped!
(By nothing I meant very little to none).
