Three significant figures would be 45.0 since it would end with the nine so you look at the next digit to see if you round up or it remains the same. It is greater than five so round up to zero. This makes the ones place also go up so the answer is 45.0 The zero after the decimal counts as a significant figure.
Answer:
answer it by yourself and own way
Answer is: Louis Pasteur (1822-1895) disproved spontaneous generation. He boiled liquid with proteins and other nutrients in S-neck flasks and regular flask to kill all microorganism present. In regular flask liquid showed changes when exposed to air and in S-neck flack there was no change (microorganism can not getting in the flask because the S- neck). When he removed S-neck, liquid changed because microorganisms came in liquid.
Pasteur showed it was not the air itself but particles within the air that had microorganisms.
