subject for的用法和樣例：
例句
- He yapped on the subject for hours.
他就那個(gè)問(wèn)題羅嗦了好幾個(gè)鐘頭。 - She has been wrestling with this subject for two hours.
她鉆研這個(gè)問(wèn)題已經(jīng)兩個(gè)小時(shí)了。 - A cause or subject for laughter.
笑因，笑者笑的原因或對象 - Which is the most interesting subject for you?
哪個(gè)科目對你來(lái)說(shuō)最有趣？
