Apologies in advance as I am sure this has come up before and I only visit this thread sporadically but...there is a regular tendency for us to gripe in here about the ambiguous cases of two answers which seem interchangeable. One I have not yet seen mentioned but got two of this sort today are the opposites which are NOT opposites. Today I saw "beginning-middle" as an opposite pair.
It seems this is meant to be an easy one that you fill instantly to narrow down the field for more subtle ones that aren't immediately obvious but I have to skip it and return with the rest of the "hmmmm" file and get it only when it becomes clear nothing else fits.
The problem is this is not a binary grouping The opposite of beginning would naturally be..."end". "Middle", while clearly not the beginning, is not its opposite either. It is curiously enough..in the middle. By definition if there is a beginning and a middle there would have to be an end as well.
It seems to be used here in the vein of center vs extremity, but again that is not as immediately clear as I think was intended and I could only confidently fill it by elimination as the last one of the section (and even then I was waiting for that cursed pair of unexpected red X's and the explanation that in some obscure southwestern Kentucky colloquial variant, middle actually means mushroom ... which would of course be the opposite of tree