Q: Given a scientific passage and an answer, generate a question for the given answer.
Passage: Plants and other autotrophs make food out of "thin air"at least, they use carbon dioxide from the air to make food. Most food is made in the process of photosynthesis. This process provides more than 99% of the energy used by living things on Earth. Photosynthesis also supplies Earth's atmosphere with oxygen. Answer: photosynthesis
A:
What process provides more than 99% of energy?