GMAT Sentence Correction (SC) | The shift from traditional dentistry to cosmetic dentistry

The use of noun + present participle (-ing) modifier is tricky. Such usage is correct when the emphasis is required on the noun, but wrong when the emphasis is required on the action, i.e. the -ing modifier..

For example:

I learnt about John getting a promotion... wrong because the emphasis is required on "getting a promotion"-"getting the promotion"
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