Answer:
1 ). Earthworms have what are called closed circulatory systems. Closed circulatory systems are those in which the blood is kept in a closed system of vessels, like in humans. Open circulatory systems are when the blood is pumped into a body cavity called a hemocoel, allowing the blood to surround the organs.
2). Crayfish also have an open circulatory system. Blood flows into the heart through dorsal ostia, and is pumped into body sinuses through arteries at both the posterior and anterior ends of the ventricle.
Explanation:
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Nitrogen dioxide is covalent, others are ionic. ;)
The question is asking to explain the aquatic environments are more likely to have winter ice and base on my research, the answer would be the water in fresh water ecosystems like lake, ponds, and rivers are more likely to freeze over in winter because the salt dissolved in marine environments prevents the water from freezing.
The answer is true, the first option
They show both the characteristics of a living and a non-living.