The troposphere is shallowest or narrowest at the poles, and deepest or thickest at the equator. At the geographic North and South Poles, the troposphere reaches only 4 miles high, while at the equator, it extends nearly 12 miles high.
Volume? Is that what you mean?
It is just called: a simple fracture. BUT when the bone does pierce the skin it's called a compound fracture. <span />
Answer:
B. often use tube feet to move around in their environment
Explanation:
Tube feet are tiny tubular projections of echinoderms on the underside (oral side). They are a member of the echinoderm water vascular system.
Tubular feet are used for feeding, breathing and shifting. They are arranged around the sides, in grooves. They work by hydraulic pressure. They are used to transfer food in the centre to the oral mouth, and may stick to surfaces. Tube feet allow certain animals to stick and travel slowly to the ocean floor. for example starfish uses tube feet for the above functions.
Hence, the correct option is B.
