If something pertains to something else, it is related or has to do with something else.
The word abouts means when something is connected or associated with.
The word ocular is basically another word for eyepiece. It basically means that something else is connected to the eye in order to see it. An example would be a microscope; you look through the ocular to see the magnified image.
Something is imbedded in something else when it is stuck into it.
exchange something for something else in other word's trade.
Buy is a word to obtain something but by giving something else. Purchase can be the similar word for buy.
complete and something else.
exchange something for something else in other word's trade.
It means to replace something, with something else that is equivalent.
Variables or factors. I hope that helps. A catalyst
The word is actually "misCible" meaning something that can be mixed with something else.
Alternate. substitute (verb)