Amber has begun to cry when she is dropped off at daycare. this development likely occurred at what age?

a. one year old
b. two years old
c. three years old
d. four years old

Which of the following is not a possible cause of conduction deafness? a) cochlear nerve degeneration b) middle ear infection c) impacted cerumen d) otosclerosis

How will your health most likely be affected if you follow the recommended guidelines for sleep, rest, and physical activty

[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.