1 . 尽管她没有提到任何名字，但大家都知道她指的是谁。(refer)
Although she didn’t mention any names, everyone knew who she was _____.

2 . 他被认为是最努力学习的学生。
He is ________ ________the most hard-working student in class.

3 . Many children ________________(留下) in the countryside when their parents flood into the big cities for jobs. (根据汉语意思填空)