he was very excited because he had long __(dream)of becoming a college student 为什么是dreamed

问题描述:

he was very excited because he had long __(dream)of becoming a college student 为什么是dreamed

had+过去分词 表示过去的过去.
当同一句中,有两个动作都发生在过去,并且时间有先后的话,先发生的用过去完成时,后发生的用一般过去时.