Maria believes that high doses of caffeine speed up a person's reaction time. In order to test her hunch, she has five friends each drink three 8-ounce cups of coffee and then measures how quickly they are able to push a button when a tone is sounded. What is wrong with Maria's research strategy?

Advertisements are filled with images of extremely fit and sometimes even underweight people. what is an example of how these images might positively influence a person’s health choices? a) choosing to use weight loss supplements to increase weight loss b) electing to skip meals to reduce calorie intake until target weight is met c) figuring out ways to purge after meals to reduce the number of calories consumed d) finding ways to increase physical activity to burn calories and increase heart weight

What are possible signs and symptoms of drug addiction? check all that apply. declining physical appearance and health failing to meet family, school, or work obligations needing less and less of a drug to get the same effect using drugs when there is no health benefit failing in attempts to stop using a drug stealing to get drugs

[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.