Since I began to work here three years ago,this factory___in size_英语解答

Since I began to work here three years ago,this factory___in size. A.had doubled B.has doubled
为什么B解释下谢谢

人气：495 ℃　时间：2019-11-23 14:05:09

解答

B since 加过去时,主句要用现在完成时,如：
It has been 5 years since I came here.