Cofunctor
上函子, 反變函子
??? 情景例句
Hi. What can I do for you?
嗨 。我能幫你嗎？
The police crept up from behind and took the gangster by surprise.
警察悄悄從背后繞過去，出其不意地將歹徒逮捕。
May I know the quantity you require?
請問你們需要多少數量的貨物？