1. a matter of
a matter of意为“一个……的问题”，后接名词、代词等。如：
It was a matter of life and death for them.
对他们来说这是生死攸关的问题。
而a matter of (seconds / weeks / hours, etc.)意为“不多于，只有”。如：
The ambulance arrived in a matter of minutes.
几分钟后救护车就到了。
The bullet missed his head by a matter of inches.
子弹从他头部几英寸远的地方飞过。
[知识拓展]
matter用作名词，表示“问题；麻烦事；物质”；用作动词，意为“关系重大；要紧”。构成短语有：as a matter of fact实际上，不瞒你说； to make matters worse更糟糕的是；no matter how / what ...不管怎样/什么……；the matter 有问题；What’s the matter with ...? ……怎么啦? It doesn’t matter. 没关系。Does it matter if ...? 如果……要紧吗？