Answer:
The phylum of mollusks includes more than 50000 known species, found in freshwater ... Echinoderms have a water vascular system originally used to collect and ... by expanding or contracting their rows of tube feet in a particular sequence.
Explanation:
true
Answer:
The carbon cycle
Explanation:
The burning of fossil fuels returns the carbon (of which they were made of) back into the atmosphere.
The answer is b photosynthesis
A. is your correct answer.