什么是人机工效？

• A. How about her
• B. What happened
• C. I believe he
• D. poor Alan
• E. I can imagine
• F. I guess something
• G. ls she fine now
• H. I don’t know
  Robyn: Has Alan shown up yet
  Scottie: Nope. (56) might have come up.
  Robyn: I wonder what happened.
  Scottie: (57) . I hope it’s nothing serious.
  Robyn: Last week his sister was admitted to the hospital.
  Scottie: Oh (58)
  Robyn: His sister had a car accident last week.
  Scottie: (59)
  Robyn: She’s still in a coma(昏迷).
  Scottie: Oh, (60) . His sister is the only he has left since his mother died last year.