Answer:
These are things that won't be going away. Natural gasses and fossil fuels will likely run out someday or become much harder to find. When you use these sources of energy, they won't be going away and therefore will be sustainable because we can always continue using them.
Does that make sense?
Explanation:
SOS:
The answer is <em><u>gametes!</u></em>
<em>Hope this helps!</em>
The answer is the last choice, or ‘ GG and Gg’
