The cardiovascular system is composed of the heart, blood vessels, and blood. which is the best analogy to this system and its parts?
a car engine, a gas tank, and gasoline
a coffee maker, coffee filters, and coffee
a water pump, water pipes, and water
a can of paint, the pressure of a hand, and paint

How do your peer relationships affect your overall health status? what can you do to improve your peer relationships?

Which of the following is an argument against buying local fruits and vegetables?

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine.what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.