I,ve been a student there for nearly two and ()half years 括号里填a?为什

I,ve been a student there for nearly two and ()half years 括号里填a?为什

two and a half years 两年半
固定搭配

a指的是一个半年，所以总的来讲是两年半

句子的意思是:在这,我已经做了两年半的学生了. two and a half years 是两年半的意思