awnser is high concentrations of oxygen
Answer:
C. when an origanism changes tropic levels to look like another organism
Such direct observational evidence is limited, however, and clouds remain the biggest source of uncertainty--apart from human choices to control greenhouse gases—in predicting how much the climate will change
I would say D narrow temperature. Most other planets are too hot or cold to sustain life.
two strands of DNA are held together by weak hydrogen bonds.
