Why were the school implement the healthier us school challenge

Which action best increases one’s stamina a) exercising when you feel like it b) saving so much that one like sleep c) refusing to exercise to save the energy needed to work d)exercising on a regular basis

[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.

Kelly is 33 weeks pregnant and her doctor has scheduled her for a procedure to remove a small amount of fluid to check for the health of the fetus. the procedure is called .