21.   The E. coli bacteria lives in the intestines of cows and other animals.

22.   They learn about the pH quality of the water, bacteria living in it, temperature changes, and oxygen and other trace elements.

23.   To determine if the bacteria lived in the simulated Martian environment, Kral said he measured the amount of methane produced inside the sealed culture dishes.

24.   Serratia bacteria live in human intestines and are also common in the air.