1. 英语语法
  2. 动词的语态
  3. 短语动词的被动语态

短语动词是一个整体,不可丢掉后面的介词或副词。

例句:

This is a photo of the power station that has been set up in my hometown.

My sister will be taken care of by Grandma.

Such a thing has never been heard of before..