当一个单数可数名词,用在介词后省略冠词,一般表示“抽象意义”。如果加了冠词,则表示具体意义。比较:
When my time comes, I wanna be buried at sea.
When my time comes, I wanna be buried in the sea.
上述用法与下面的表达类似:
We often travel by bus.
We often travel in the bus.
He was lying in bed.
He He was lying on the bed.