英语冠词语法题by the time he was 38,he had become principal of a university.其中,为什么principal 前面没有冠词?

问题描述:

英语冠词语法题
by the time he was 38,he had become principal of a university.其中,为什么principal 前面没有冠词?

principal,head,monitor等这类表示“职位、头衔”的名词一般前面不接冠词,尤其是作宾语补足语的时候,再如
He was elected president of the US
He became monitor of his class later