What is the Texas Health Services Authority (THSA)?

[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.

Wjat are substances intentionally added to food to produce a desired effect?

Which practice is harmful to the land? a. using animal waste as fertilizer b. composting with peels from commercial fruit c. throwing paint cans in the garbage d. cutting the lawn with a gas-powered mower