I want to say A only... Hope I helped!!
1.
- The changing of liquid to a gas.
2.
- The major source of pollution.
3.
- Carbon dioxide and water vapor trapping heat given off by Earth.
4.
- Layer absorbing ultraviolet rays.
5.
- The changing of a gas to a liquid.
6.
- Layer responsible for reflecting radio waves.
7.
- The layer in which weather changes.

Answer:
Two essential measurements to calculating average speed are Distance and Time
Explanation:
hope it helps you
The correct name for the N3- ion is a nitride ion.