Who developed the practice of participant observation?

You are traveling down the road and the hopd flies up- a. look out of the gap between hood and cowling b. look out the left window c. stop the car d. turn on your four-way flashers e. use stop signal given with arm 2. you are driving down a dark, country road and the headlights suddenly go out- pull off the side of the road and stop flash your break lights activate your four way flasher have scotty beam you up turn your parking lights on 3. you turn on a crowded street and the accelerator pedal sticks- turn ignition off shift to neutral apply the brakes reach down and pull pedal by hand use the of toe of your food to pull pedal up

[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.

Have a friend or family member complete the questionnaire. make a prediction about that person’s wellness and justify your prediction using two or more complete sentences.