Pick your answer from: 1. disease; 2. chemicals; 3. waste; 4. bamboo; 5. engines; 6. sleep; 7. energy; 8. food;
Q: Fact 1: Biofuel is used to produce electricity by burning. Fact 2: Energy is created when objects are burned. Given the two facts above, what is biofuel used to produce?
A:
7.