为什么a few minutes ago的few前要加a?

为什么a few minutes ago的few前要加a? The meeting stopped a few minutes ago. 为什么是every few minutes而不是every a few minutes a few minutes的中文 can you spare me a few minutes 的"a few minutes"前面为什么不用介词“for in a few minutes took a few minutes a few minutes是什么意思 a few more minutes a few minutes a few days ago为什么用a few ____there a telephone call___Dick a few minutes ago?