Answer:
Imagine studying a cell. That cell has billions of things you can learn about. Now imagine 37.2 trillion cells each a little bit different but still similar. Now imagine that multiplied by all the different people there are on earth. Now then include all the other types of living animals.
That's biology
Answer:
<h2>Secondary air pollutants are pollutants which form in the atmosphere.</h2>
Explanation:
Examples of a secondary pollutant include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight; NO2, which is formed as NO combines with oxygen in the air; and acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water.
Answer:
2nd level has 4 orbitals. An f sublevel has 7 orbitals.
<span>D. the crust
Thats the surface of the earth.</span>