Which type of research study is set up so that neither subjects nor investigators know which is the active group and which is receiving a placebo? question 10 options: case control double blind clinical trial epidemiological

[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.

Rotation of the head is made in atlanto-occipital joint or not?

Evaluate the scenarios and select the one that demonstrates the training principle overload. kai swims faster and faster every day. katie stays consistent in her routine. maggie does kickboxing daily so she can win a kickboxing match. sarah usually likes to run, but tries swimming. !