查询词典 prepositional

But when the uncountable noun is modified by and adjective or a prepositional phrase, it becomes countable and therefore can be modified by the indefinite article to refer to an individual or a specific type.

英语的不可数名词不能冠以不定冠词，但当不可数名词受到形容词或介词短语的修饰或限定时却变成可数名词，因而可以受到不定冠词的修饰，表示某种个别的或特殊的情况。

The uncountable noun should not be preceded by the indefinite article. But when the uncountable noun is modified by and adjective or a prepositional phrase, it becomes countable and therefore can be modified by the indefinite article to refer to an individual or a specific type.

英语的不可数名词不能冠以不定冠词，但当不可数名词受到形容词或介词短语的修饰或限定时却变成可数名词，因而可以受到不定冠词的修饰，表示某种个别的或特殊的情况。

I'm not an actor. I'm a professor of paleontology.

我不是演员，我是古生物学教授

Spider Network Web site that is a very image of the name.

网络蜘蛛即Web Spider，是一个非常形象的名字。