The CDC recommendations for exercise for health maintenance include:
A. Weekly resistance exercise or aerobic activity but not both
B. 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity
activity each week
C. Resistance exercise 1 day a week or more
D. 250 minutes of moderate-intensity aerobic activity or 150 minutes of vigorous-
intensity activity each week

[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.

American college students invented football by combining what two sports?

When children are young and go to the doctor, the doctor will give them booster shots. this re-exposes the children to a dead portion of a disease to them build immunity.