Hi Yoong, maybe "at witch" is correct, but I'd never say it in any case. I'd only use "where". This must be related to the fact that I always try to avoid forms putting a preposition in front of "which", and avoid "which" itself when it is followed by a restrictive relative clause.
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KooyeenHi Yoong,
maybe "at witch" is correct, but I'd never say it in any case. I'd only use "where". This must be related to the fact that I always try to avoid forms putting a preposition in front of "which", and avoid "which" itself when it is followed by a restrictive relative clause.