Then he _____ (work) there for about eight years.

问题描述:

Then he _____ (work) there for about eight years.

has been working表示一种持续的状态

has been working
for加时间段是现在完成时并且是延续状态

The he has been working there for about eight years.
has been working是现在完成进行时,表示过去一直延续到现在的动作或状态.
他在那儿一直工作了8年