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:
Explanation:
Hence, the correct answer is 'Nuclear membrane'.

Answer:
1. make an observation 2. ask a question based on your observation. 3. form a hypothesis/ make a prediction 4. do a test or experimentation 5. analyze data 6. form a conclusion
Explanation: