The answer is C. A variety of antibiotics
Normally, oxygen from the blood cells supply your muscles with the energy it needs to carry out certain actions. However, when there isn't enough oxygen to support the muscles, it produces lactic acid, or fermentation, to make up for the oxygen. (That's why you get that burn-y feeling whenever you exercise!)
They use their beaks and they push down really hard to stick it
<span>The answer should be: D) water supply
</span>Water is a perishable resource and its supply will limit how much population that an area could hold. <span>With a bigger population, the competition for water will be higher which make water shortage more likely. Others density-dependent limiting factor than competition would be disease, parasitism, and predation.
</span>
