Answer:
C) when nuclear fusion begins in the core
Explanation:
- <u>The protostar is a main-sequence star that has a core temperature that exceeds abut 10 million K and is needed for the hydrogen to operate efficiently and the </u><u>length </u><u>of this process depends on nature and the stellar </u><u>mass</u><u>, as the huge massive star have a greater and bigger core and fusion takes fast.
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- A protostar is also called as primitive star and represents the earliest phases of the process of the stellar evolution and takes place after it leaves form the main sequence star.
Answer:
The correct answer is D
Explanation:
During the 20th century, there was an increasing interest in the environment. The impact of human activity on the environment has been observed locally since centuries. Pollution of canals and chimneys in crowded urban areas etc were all causes of concern.
However, with a better understanding of our earth and increase in Medical knowledge of the 20th century, we could observe how our activities were having a global impact on the ozone layer and the melting ice caps.
Evidence was also provided on how human health was affected by this. The use of fossil fuels was not only directly damaging to the atmosphere, it was also dangerous for humans e.g. carbon monoxide produced by car emissions.
Religious and ethnical problems.
It was one of the largest empires of the world with many different ethnicities. The problem was to unite people under one rule.
Another problem was communication. It was hard to transfer knowledge and news to all parts of the empire because it was too large.
Answer:
74 miles per hour
What is the maximum wind speed of the storm after 36 hours of monitoring? winds of 74 miles per hour or greater.
Explanation:
hope this helps
B is the answer hope this helps