B. the reason why scientists do he experiment more than once is because they have to compare the first attempt and the second attempt . Because if they are different they have to figure out what id the different or aka what is different. hope this helps ;)
Answer:
Number 3
Explanation:
Number 3 or C is correct, "action of white blood cells when certain bacteria enter the body." This is the correct answer because white blood cells are in your body to fight off infections. some peoples immune system see these bacteria on the peanut, egg, or milk as an enemy so it tries to fight against it even though it is harmless to the body.
Answer:
la verdad no se perdón ame