Wet-mount preparation

What is the advantage of using wet mount preparation instead of dry mount preparation?

I was thinking about installing a wall mounted pot filler in our kitchen. What type of fitting and mounting does this require. I am using ½” copper to a thread male. I will secure the pipe to the stud. Is this correct. How far out does the thread need to stick out of the wall.

If I want to become an obstetrician, what will I have to major in in college and will I be able to do like job shadowing or something similar while I'm in college?

What is the advantage of using a wet mount preparation instead of a dry mount preparation in the study of living cells? PLEASE HELP!