Why is bleeding air out of a hydraulic system important?

Aduty of the adult assigned to supervise a group of children is to a. check on the children at least every 20 minutes. b. keep the children within earshot. c. give the children a list of "don'ts" concerning behavior. d. conduct a name-to-face check when transitioning to the playground

Which of these is a controllable risk fator for disease

The amount of oxygen that is actually used by the body during the rest or a hand workout is determined by the heart rate, the stroke volume, and the amount of a. blood circulating in the vascular system b. oxygen removed from the vascular system c. oxygen provided to the vascular system d. blood that individual has in the body e. hemoglobin in the red blood cells