Answer:
A closed system is a physical system that does not allow transfer of matter in or out of the system, though, in different contexts, such as physics, chemistry or engineering, the transfer of energy is or is not allowed.
Answer:
B
Explanation:
Arteries and arterioles (small arteries) have muscular walls. They're the main blood vessels involved in vasoconstriction. ... Capillaries are tiny, thin-walled blood vessels that can't constrict.
Answer:
He need to eat 275 g
Explanation:
2000 = 100
5500 = 2000÷100= 20 = 5500÷20 = 275
He need to eat 275 g