Answer: Some sticklebacks were stranded in lakes that were formed in the ice age
The control group outs the one that you don't change. The reason you don't change it is because you use it as a comparison with the other groups.
1. k
2. d
3. c
4. j
5. f
6. e
7. l
8. h
9. g
10. b
11. i
12. a
I believe these are all right correct me if I am wrong
I don't think doctors are supposed to do that but if they are I'm guessing it's probably to kill a infection of some kind or speed up the healing process