What is the name of the kind of stretch that involves stretching as far as you can and then holding for 10-30 seconds

A. PNF
B. Ballistic
C. Dynamic
D. Static

[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.

Why is important to cover your hands and feet in cold weather? a. they are furthest from your heart. b. they are often last to receive blood flow. c. they can suffer from tissue damage in cold weather. d. all of the above

Which of the following is also referred to as "swayback"? a. kyphosis b. scoliosis c. lordosis d. none of the above