True.
In the upper layers of the atmosphere, it blocks UV radiation from the sun; however, in the lower layers, it is a pollutant.
Answer:
Number 4 here.click on the picture
Answer:
Option C
Explanation:
The null hypothesis is the problem statement and alternative hypothesis is counter of the null hypothesis.
Hence, the null hypothesis here is the rate of extinction was neither higher nor lower when there were sudden climatic changes (asteroid strike)
And alternate hypothesis is "the rate of extinction was either higher or lower when there were sudden climatic changes (asteroid strike)"
Hence, option C is correct
