What associations does a dog make when being conditioned to drool at the sound of the bell? the dog associates the bell with a sound. the dog associates the food with good taste. the dog associates the sound of a bell with getting food. the dog associates the sight of a person with drooling?

[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.

How could natural selection best be used to explain the evolution of the white fur of arctic fox

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.