The type of learning that involves problem-solving is called "insightful learning". This is a good way to learn in the sense that it really makes you understand that material.
The correct answer would be nuclear energy. The other answers would be fossil fuels because they are naturally made.
Answer: they grow bigger and stick together
Explanation:
We could do thing with our hands without having to use some of our energy in getting up to try to balance on our two rear legs.
