has been to 什么意思

Question

如题所述

Answer 1

has been to
去过; 曾经去过某地; 到过; 去过......
He has been to Africa.
他到过非洲。
The technique has been to mutate the genes by irradiation or chemicals.
该技术是通过放射线照射或者使用化学方法使基因变异。