但该大学的一名教授称，这位学生花了大约两天时间才做出证明。

It took him about two days, however, according to a professor there.

youdao

但该大学的一名教授称，这位学生花了大约两天时间才做出证明。

It took him about two days, however, according to a professor there.

youdao