Who has responsibility to ensure the safety of food?

What is one way in which an active listener can confirm understanding of a message?

[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.

According to myplate guidelines, grains should make up (less than one-fourth, more than one-fourth, about one-fourth) of your plate, fruits should make up (less than one-fourth, more than one-fourth, about one-fourth) of your plate, protein should make up (less than one-fourth, more than one-fourth, about one-fourth) of your plate, and vegetables should make up (less than one-fourth, more than one-fourth, about one-fourth) of your plate. just answered it; about one-fourth, less than one-fourth, about one-fourth, and more than one-fourth