He is now studying under the guidance of Professor Green.

他现在正在格林教授的指导下学习.

You must be our long-expected guest, Professor Green from University of Pittsburgh!

您一定是我们期盼已久的客人，从匹兹堡大学来的格林教授吧。

You must be our long - expected guest, Professor Green from University of Pittsburgh!

您一定是我们期盼已久的客人, 从匹兹堡大学来的格林教授吧.