1. That is to say, I believe that the Internet has positive effects on our lives. (P34) 也就是说，我相信因特网对我们的生活产生正面的影响。
That is to say: That is; in other words 也就是(说)，换言之，亦即
常用来进一步解释前面说过的事情。这是个固定短语，在句中作插入语。
1. My boss has asked me to attend a lecture about the use of the Internet three days from now，that is to say，on Friday．
②John is a Londoner，that is to say，he lives in London
effect have an effect on对……有影响；对……起作用
