20.
They told me that my answer was too short so I'm just adding this on, don't mind me.
<h3>
Answer:</h3>
The goal of an engineer is to find ways to keep people safe, and to solve their problems efficiently and effectively. Every engineer has a goal, but not every engineer knows what it is. Fewer still don’t have a plan for getting there. Be exceptional—know your goals and make them happen. If you can do this, you’re already well on your way to an extraordinary engineering career.
<em>Please mark me brainliest</em>
The answer i believe is d
Answer:
there could have been low production
All living things contain carbon so an argument could be made that carbon was the basis. Or it could be oxygen because all living things in one way require oxygen to live, even plants and fish who pull oxygen from the water molecules.