She has bitten her nails (down) to the quick.
她咬指甲（一直）咬到肉.
She certainly won't marry again once bitten, twice shy.
她肯定不再结婚了--所谓一朝被蛇咬, 十年怕井绳.
He was never interested in cooking before, but now he's been bitten by/he's got the bug.
他以前对烹饪从不感兴趣, 但是现在可著迷了.
