N-SING [with poss]习惯性行为;惯用伎俩 If you say that something is someone's stock-in-trade, you mean that it is a usual part of their behaviour or work. 习惯性行为;惯用伎俩
Patriotism is every politician's stock-in-trade.
爱国主义是政客们的惯用伎俩。
Delicious potted shrimps and prawns were once the stock-in-trade of the harbourside cafe.