英语翻译The old man,____B____ abroad for twenty years,is on the

英语翻译
The old man,____B____ abroad for twenty years,is on the way back to his motherland.
A.have worked B.having worked

这句话有插入语,或叫非谓语,作用是修饰说明
整个句子应该是 The old man （主语）is（谓语） on the way back to his motherland.而having worked abroad for twenty years就是非谓语,修饰the old man,如果选A,那么一个句子就出现两个谓语了,一个是have worked,一个是is,显然不对!
像类似的知识你可以学习一下非谓语短语的知识点,一般非谓语为现在分词短语,过去分词短语和不定时短语为常见!