The Smiths _____ ( work) at this school since 1998.

问题描述:

The Smiths _____ ( work) at this school since 1998.

The Smiths have been working/have worked at this school since 1998.
史密斯夫妇从1998年开始在这个学校工作.
用have been working表示现在还在这个学校工作
用have worked表示现在不在这个学校工作了.