He has been working in the lab for two hours.

他已经在实验室里工作了两个小时。

youdao

I've spent many happy hours with you in the lab and the classroom.

我在实验室里、教室里和你们一起度过了许多美好时光。

youdao

I 've spent many happy hours with you in the lab and the classroom.

我在实验室里、教室里和你们一起度过了许多美好时光。

youdao

I 've spent many happy hours with you in the lab and the classroom.

我在实验室里、教室里和你们一起度过了许多美好时光。

youdao