Answer:
8. respiratory system
9.circulatory system
10.digestive system
11. circulatory system
12. e.coli, pro-biotic bacteria/enzymes
Explanation of 12:
Lactic acid bacteria and Bifidobacteria are two important types of gut bacteria, which are autochthonous ones from birth or acquired from digested food. Lactobacillus and Leuconostoc spp. are the main lactic acid bacteria found in the human intestine.
