Answer:
Testing positive for HIV means a high chance of death and a good chance of lower reproduction rates. But some people are immune to HIV, which makes them more evolutionarily fit, likely to live longer, likely to reproduce more, which would increase the frequency of the immune allele in the population. Over time, this increase in frequency of the gene that causes immunity could spread across the human race and cause it to evolve.
The correct answer is C, Oxygen.
During aerobic cellular respiration, oxygen combines with hydrogen ions and water is released as a by-product of respiration.
Explanation;
Cellular respiration allows organisms to release energy stored in chemical bonds of glucose, and other nutrients. The energy in glucose or other nutrients such as fats is used to produce ATP, which cells use to supply their energy needs. During aerobic respiration (in presence of oxygen), oxygen is reduced and water is produced together with carbon dioxide as by-products.
A crevice is a narrow opening resulting from a split or a crack. <span />
I believe the answer is the location of energy sources