I need help with as many as you know pls also i need them soon

[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.

A62-year-old man is being treated for an acute myocardial infarction. he originally came to the ed with substernal chest pain and diaphoresis. given his risk factors of hypertension, diabetes, tobacco use, and family history, he is considered high risk. an ecg in the ed reveals a left-bundle branch pattern, and cardiac enzymes are elevated slightly. after a focused evaluation in the ed, the patient receives iv thrombolytics. although his bundle branch pattern never resolves, the patient is chest pain-free and haemodynamically stable after thrombolysis. two days later, however, the patient reports episodes of recurrent chest discomfort and shortness of breath overnight. in evaluating for potential myocardial reinfarction, which of the following is the most appropriate diagnostic test? - creatinine kinase- dynamic ecg changes- lactate dehydrogenase- myoglobin levels- troponin i level

Analyze the impact of the availability of health services in the community and the world. research various school and community health services for people of all ages such as vision and hearing screenings and immunization programs. identify situations requiring professional health services for people of all ages such as primary, preventive, and emergency care.