同学你好，该知识点来自沪江网校《大学水平直达CATTI二级（笔译+口译）【三年畅学开学季专享班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好
be/bear witness to这个词组已经形成了一种固定用法，在用的时候其中的witness往往不随人称变型，可以参考以下例句：
Now we are witness to the ward, and fulsome of its occupants.
Globe and Mail (2003)
The popularity - and growing political force - of ' mummy' websites are witness to that.
Times, Sunday Times (2011)
The bench players themselves are witness to the pressure that he puts on them.
Times, Sunday Times (2017)
希望对同学有帮助，祝学习进步~