Answer:
Nitrogen cycle
Explanation:
Nitrogen fixation is the process by which atmospheric nitrogen is converted by either a natural or an industrial means to a form of nitrogen such as ammonia. In nature, most nitrogen is harvested from the atmosphere by microorganisms to form ammonia, nitrites, and nitrates that can be used by plants.
As any other ancient civilization, the Sumerians were traders as well. And they had a few good reasons to do this.
Because they traded, their trading partners were less likely to attack them, because it would hurt their economy as well. Furthermore, they didn't produce everything they needed and traded those goods with goods which they produced too much of.
And lastly, through trade they could also get exotic goods which they would have never gotten otherwise.
Answer:
lava flows are very hot, thin and runny. When it cools is has a smooth to ropey texture because of the low silica content which makes it cool quickly. Pahoehoe flows creep along generally at less than 3 feet per minute but some flows have been measured at over 20 miles per hour.
Explanation:
it is A
I think the correct answer from the choices listed above is option B. Keratin is the protein in mammals which shows only a primary and secondary structure. Keratin is a fibrous protein forming the structural constituent of hair, feathers, hoofs, claws and many others.