<h3>
Answer ↓</h3>
The hardest natural substance is a diamond.
<h3>
Explanation ↓</h3>
Made entirely of carbon, diamonds are the hardest natural substances.
Diamonds can be scratched, but it's hard to do so.
hope helpful ~
I think the correct answer would be combustion. The technology that is used in dealing with yard waste to energy would be combustion. Among the choices, it is the only process which involves the release of heat which could be used eventually for other processes.
Answer: Claw print
Explanation: claw print because a claw is part of a body unlike the other options.