Jane is researching air quality levels in large cities. which element should represent about 80% in each of her samples?

The correct answer is nitrogen.

Explanation:

A layer of gases, generally known as air, which envelopes the planet Earth and is retained by the gravity of the Earth is called the atmosphere of the Earth. The dry air by volume comprises 78.09 % nitrogen, 0.93 % argon, 20.95 % oxygen, 0.04 % carbon dioxide, and smaller concentrations of other gases. Thus, when one is examining the quality of air in large cities, the element nitrogen should come about 80 percent in each of the samples of the air taken.

it enhances antibody production by t cells of the adaptive immune system.

hope i'm right

explanation:

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.