What involves mainly T cells and leads to the destruction of cells that are infected by viruses?

The forms a good substance into small balls and then pushes them into the

[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.

If you feel pain while stretching, you should do any of the following except: a. stretch farther. b. back off the stretch. c. find an alternative. d. stop stretching.