I think the first one is b
Answer:
D.
Explanation:
Plants take in CO2 and turn into Carbo.
That's the most efficient example
Reduce amount of time you take showers and use the bathroom, as well as stop leaks
Discriptive investigation never include a hypothesis.
Answer:
Support, movement, protection, blood cell production, calcium storage and endocrine regulation
Explanation: that’s what makes us survive.