The word apostrophe has the normal S plural apostrophes.
The correct spelling is apostrophe (the punctuation mark ' )
The plural way to spell studio is studios.
The plural is resources.
The plural is cantaloupes.
The plural is hooves.
The plural is cherries.
The plural is roses.
The plural is "emeralds."
Plural of "madam" is "madames". (same root as the English styling "Dame", the equivalent of the formal honorific "Sir". ) "Madam" is shortened with an apostophe in conversational usage, as "ma'am".
The plural is bridges.
The plural is "recesses".
The plural of "roar" is "roars".