In a healthy person, how might coughing and sneezing protect the respiratory system ?

What is a small pants but the m word mean my friends call me that a lot im 5 year old

[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.

When data collected on the performance of a healthcare facility suggests that quality standards have not been met, what is one method that can be used to correct the problem?