TOEFL Listening: ETS-TOEFL听力机经 - X37938PP0WV9Z1HFP$

Why does the director mention what the poster says? A. To point out that he is not qualified to he a leader for the trip B. To indicate a problem with the student's proposed C. To suggest him not to take a walk high Line D. To explain the bus wouldn't be available with only fifteen students