Answer:
I think its A
Explanation:
Because the reason why airplane have closed windows is because we can't breathe in carbon dioxide when we go up. Of course there is oxygen just not a lot as we go up. Why would there be helium in the air? We would sound weird when we skydive.
Answer: A
Explanation:
With a decrease in predators there is no challenge for the prey and population growth can become uncontrollable
Hope this helps
Answer:
B. Antibodies react specifically with an antigen.
Explanation:
Serological tests are blood tests that look for antibodies in your blood. They can involve a number of laboratory techniques. Flucculation tests are based on the precipitation that takes place when antibody and specially prepared antigens are mixed together
Hi , energy conservation is the practice of decreasing the quantity of energy used. The conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant.