I believe the answers are A. C. D.
Answer:
1. to carry oxygen from the lungs to the body tissues
2. seven (7) or (4)
3.Humans can't live without blood body's organs couldn't get the oxygen and nutrients they need to survive,
Explanation:
A structure formed from molecules that combine to make up cells is called an atom.
Explanation:
Conservation of Energy in Living Systems
Energy changes form as it flows through an ecosystem, but the total amount of energy in the system remains constant. Food chains show how energy flows in an ecosystem. ... The chemical energy stored in producers is passed to consumers, organisms at higher levels on the food chain.
