He__there fo twenty years since hecame to this town.a.has worked b.worked c.work d.have worked
问题描述：
He__there fo twenty years since hecame to this town.a.has worked b.worked c.work d.have worked
为什么不选a,主语是第三人称谓语动词该用has吧？
答
A 自从他来这个城镇已经住了20年了,从过去到现在用完成时
补充：如果你题目没打错不可能选D 的,主语是第三人称当然用单数has