Which statements accurately describe the actions needed to perform aid on a choking infant? check all that apply.

perform the procedure in a sitting position.
position the infant face down on your forearm.
rest the infant face up on the floor.
thump the infant’s chest with the heel of your hand.
begin chest compressions if the blockage does not clear.

multiple answers on this one, marking branliest!

[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.