<u>Answer:</u>
<em>Hydrogen and ozone are both examples of trace gases.
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<u>Explanation:</u>
Trace gases are present in minor quantities in the <em>earth’s atmosphere and all the gases except nitrogen, oxygen and argon </em>which make up the major portion of earth’s atmosphere are considered trace gases.
The respective percentages of nitrogen, oxygen and argon in the atmosphere are<em> 78.1%, 20.9% and 0.934%.</em> The process that produce trace gases is called source and the process that removes trace gas from the <em>atmosphere is called sink.
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<em>Some other examples of trace gases are carbon dioxide, neon, helium etc.
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Answer:
30vx-18v
Explanation:
Assuming the expresion is

I think the egg because it’s the start of their life cycle, or something. I don’t think the chicken came first bc the egg would be the baby and the chicken the adult.
Answer:
Blood pressure is usually defined as the pressure exerted by the blood that circulates on the walls of blood vessels. This pressure is created when the heart pumps blood continuously throughout the circulatory system.
The blood pressure have two numbers, one at the top and one at the bottom. The number showing at the top shows the amount of pressure exerted on the arteries when the muscles associated with the heart gets contracted. This is commonly considered as the systolic pressure. On the other hand, the number at the bottom shows the amount of pressure that is exerted by the heart muscles between the heart beats and this is known as the diastolic pressure.
The systolic blood pressure is more important compared to the diastolic blood pressure because it enables the person who measures the blood pressure or a doctor, to determine the risk of having a heart attack.