The best answer to the question above would be the first choice, red supergiants, and supernovas. All of the elements that are heavier than oxygen are created by the fusion reactions in red supergiants and supernovas.
Answer:
C
Explanation:
For example, if you throw rubbish on the floor or in the sea , the environment is bad. therefore , all the mess humas create it will all come back to us in some way
Answer:
The required efficiency of BOD5 removal of the plant needs to be at least 91%
Explanation:
Even though a WWTP (Waste water treatment plant) has several unit operations, it needs to have an overall treatment efficiency. In this case, it is only required to know how much BOD5 do we need to lower by removing organic matter from the water. It goes as following:

This will work for any efficiency, for any parameter you need to define. They need to be in the same concentration unit, of course.
Replacing known values, we have:

Which we will approximate to 91%, because decimal percentages do not say anything and are not currently used.
The Indian river basin that includes approximately 25% of the country's area is bound by Vindhya mountain range.
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