It is through years of research______ scientists have discovered the relationship between social media addiction and de

当前位置：高中英语 / 单选题

1. (2019高三上·高邮开学考) It is through years of research______ scientists have discovered the relationship between social media addiction and depression.

A . since B . before C . that D . when

微信扫码预览、分享更方便

使用过本题的试卷