I think the answer is letter B if I'm remembering correctly.
Answer:
Explanation:
The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. The ozone layer, which absorbs and scatters the solar ultraviolet radiation, is in this layer. The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high
Answer:
star
Explanation:
For a brief time, a supernova can shine as brightly as an entire galaxy, but will fade again over a matter of days. The explosion occurs when a high-mass star finally runs out of nuclear fuel. ... The resulting shock wave creates an expanding shell of gas and dust called a supernova remnant.
Answer:

Explanation:
÷
=
To change the ÷ sign to a × sign, swap the denominators and the numerators of the second fraction.
×
=
Directly multiply. Numerators with numerators and denominators with denominators.