three pigs的用法和樣例：
例句
- He raised thirty pigs last year.
去年他們飼養了三十口豬。 - Apart from collective pig-raising by co-operatives, every peasant household should be advised to raise one or more pigs, and this goal is to be attained by stages in a few years.
除了合作社公養以外，每個農家都要勸他們養一口至幾口豬，分作幾年達到這個目的。
