What does the phrase "closed system' mean as it relates to the cardiovascular system?  

The bones of the extremities are parts of the a-appendicular skeleton b-axial skeleton c-long bone group d-medial skeleton

When do people generally experience rapid growth for a second time? a. between the ages of 3 and 9 b. between the ages of 9 and 12 c. between the ages of 13 and 20 d. between the ages of 25 and 29 which action occurs in the third stage of cell division? a. the nuclear material of cell is copied exactly. b. the nuclear membrane disappears. c. the cell forms two nuclei d. the nuclear material separates, with half moving to either side of the cell.

What are three major influences on whether someone starts to use tobacco