If I see “such” I should look for its partner in crime, “as”
You won’t see something like “such…like”
"…most of the studies had failed to control for such variables like social class and family size…"
"…most of the studies had failed to control for variables such as social class and family size"
Meaning when using "one(s)"
Consider "Ava likes most cats, but she finds the ones owned by her next door neighbor annoying."
Notice how "ones" refers to a different group of cats than the group of cats that is first mentioned.
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