Answer:
Wow. They're both right... I still think Vaccines aren't healthy.
Explanation:
Correct answer: D) From bacteria living in their roots
Nitrogen is an essential plant nutrients, but it is metabolically unavailable to higher plants and animals. It is available to some species of microorganism by biological nitrogen fixation in which nitrogen is converted to ammonia with the help of enzyme dinitrogenase.
The process of breaking apart the two atoms in a nitrogen molecule is called nitrogen fixation. Plant obtain the nitrogen they need from the soil which is already fixed by the bacteria and archae.
Example: <em>Azobacter</em><em>,</em> Nostac
It is easy to see that the drop seems to have a "skin" holding it into a sort of flattened sphere (although there is nothing flat about a water drop in outer space.). It turns out that this surface tension is the result of the tendency of water molecules to attract one another. The natural form of a water drop occurs in the "lowest energy state", the state where the atoms in the molecule are using the least amount of energy. For water, this state happens when a water molecule is surrounded on all sides by other water molecules, which creates a sphere or ball (perfectly round if it was in outer space). On Earth, the effect of gravity flattens this ideal sphere into the drop shape we see. Although you may have heard of a "skin" where water meets the air, this is not really an accurate description, as there is nothing other than water in the drop.