Answer:
By researching, I would think that the answer is D. Ice crystals melt as they fall through a warm layer of air and then refreeze into small ice pellets as they pass through a colder layer of air.
Explanation:
<em>During precipitation formation, if temperatures are at or below freezing, 0°C (32°F), at cloud level, water in the air freezes into ice crystals, and the crystals stick together to make snow. The snow starts to fall, and if the air column is freezing cold all the way down from the clouds to the ground, the precipitation stays frozen. It simply falls as snow.</em>
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<em>Sometimes, however, a temperature inversion occurs. Normally, the temperature decreases with increasing altitude. A temperature inversion is when a layer of warm air intrudes between the ground and the clouds.</em>
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<em>Under these conditions, when the falling snow reaches the layer of warm air, it melts. Then it hits the layer of cold air just above Earth’s surface and refreezes. This all happens very fast, and the result is tiny ice pellets called sleet.</em>
The process of respiration system would not function well if the lungs was made up of only one big alveoli.
<u>Explanation:</u>
The main role of alveoli is to help the lungs to breath, for ventilation, diffusion and perfusion. The process of respiration system would not function well if the lungs was made up of only one big alveoli.
Alveoli are tiny to help the flow of oxygen and carbon dioxide, it helps the oxygen flow into the lungs and remove the carbon dioxide. If the alveoli is just one and big, then it would be hard to flow the oxygen through lungs and remove the carbon dioxide.
Therefore, it is good to have many tiny alveoli than one big one or the rib cage that protect the lungs could go through some damages.
Well, i took the test and i put artificial selection and got it right. The definition of artificial selection is "The breeding of plants and animals to produce desirable traits" So the answer is A
Hey!
Hope this helps...
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A user mentioned in the comments of one of the answers deleted: "its B" < The user (<span>lolbae0806) had mentioned this...</span>
So I believe the correct answer is:
B.) More oxygen gas became present in the atmosphere.