Explain why juggling leads to greater brain development? ​

Can someone give me one specific health problem (within unhealthy eating) and explain it. !

[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.

A5-year-old boy suddenly begins coughing while eating peanuts. he is choking and gagging. when he is brought to the ed, but he is awake and is able to give his name. on physical examination, his vital signs are stable. on examination of the chest, inspiratory stridor and intercostal and suprasternal retractions are apparent. which of the following is the most appropriate initial step in management? - allow patient to clear foreign object by spontaneous coughing- clear oropharynx with multiple blind sweeps with finger- position patient and perform back blows- stand behind patient and perform abdominal thrusts- perform emergency tracheostomy and take to surgery