idiom related to concern

[qianruS779]

Hi Dear Instructors,

I am very confused about the idioms related to concern. I want to know if concern of, concern with, concern about and concern at are acceptable in the sight of GMAC.

Thank you very much for your any insightful comments.

Best, Song

[RonPurewal]

hi,
this is the kind of thing that needs to be posted in the context of specific GMAT items, please (in the appropriate folders on the forum).

i.e., if you've actually seen these constructions tested in GMAT problems, then the discussion should center around those constructions as tested in the problems.
otherwise, we would almost certainly be discussing things that are irrelevant to the exam that you are going to take.

thank you.