Answer: A double-layered membrane called the pericardium surrounds your heart like a sac. The outer layer of the pericardium surrounds the roots of your heart's major blood vessels and is attached by ligaments to your spinal column, diaphragm, and other parts of your body.
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Answer:
They give birth to live (not eggs) babies, except for the exception of 5 speices, those who lay eggs.
Explanation:
Hello There! ^_^
Your question: What is a darker contour line usually every fifth line..?
Your answer: An indes contour is a contour line that is usually in every fifth line.
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