He works as a teather now,but he__on a farm for three years .A.worked.B.has worked 请回答选A还是...He works as a teather now,but he__on a farm for three years .A.worked.B.has worked 请回答选A还是B并解释一下为什么
问题描述：
He works as a teather now,but he__on a farm for three years .A.worked.B.has worked 请回答选A还是...
He works as a teather now,but he__on a farm for three years .A.worked.B.has worked 请回答选A还是B并解释一下为什么
答
A worked
表明他以前在田地做工了三年,但他现在是一位老师,所以选worked（过去式）
has worked 现在分词 = 到现在他还在田地做工