an education

有些不可数名词,单独使用时不能带不定冠词,但是,加上定语后,就可以带不定冠词。sensitivity → a remarkable sensitivity → a charming sensitivity → a sensitivity that delighted the critics

business $\$rightarrow a brick business

education $\$rightarrow a good education $\$rightarrow a college education

请考察下面的实例：

1. She gave her children a first-rate education. (Shaw) 她让她的孩子们接受了一流的教育。

2. You must get a thorough education. (London) 你必须接受全面的教育。

3. He received a good education. (ALD) 他受过良好教育。

4. Marriage is a lifelong business. (Galsworthy) 婚姻是一辈子的事。

5. It was a difficult business getting everything ready in time. (GPU) 把所有的事情都及时准备好是一件很困难的事。

现在可以正面回答你的问题了。你所提到的 an education 实际上暗含着一个定语: good。She has had an education. = She has had a good education. (她受过良好的教育。)这样一来, 不可数名词与不定冠词连用, 就很好理解了。