How do public safety regulations protect workers

Informal assessments are best described as a. planned, pre-made assessments developed for a specific purpose. b. scheduled observations used to gather data in preschool settings. c. unreliable observation that's only appropriate in infant and toddler settings. d. nonstandardized forms of assessment used to gather information on children's behaviors and characteristics

Many factors influence your mental and emotional health

[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.