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 ;)
Explanation:
A. chloroplast
B. vacuole
C. plasma membrane
D. Smooth endoplasmic reticulum
Two kinds of Fermentation are, Alcoholic and Lactic acid Fermentation.
B. Two protons and two neutrons
Dominant m8 hope this hleps