— She looks rather upset. She        the exam.— I guess so. It’s very difficult after all.

---The work will take me another week. I’m really tired.---I think you          as well consult an experienced worker.

—Why can your neighbor know so much about London?—He ____ have been there before.

He has      for three or four days. 

—A medical team was sent to Japan by air five hours ago.—So they ______________ have arrived by now. The flight usually takes four hours or so.