我在厦门大学博士学习的阶段，外国老师是一个美国人。

I the stage which study in Xiamen University doctor, foreign teacher is an American.

youdao

我在厦门大学博士学习的阶段，外国老师是一个美国人。

I the stage which study in Xiamen University doctor, foreign teacher is an American.

youdao