How did the fire startA．A motorist carelessly thre

单项选择题

You will hear three dialogues or monologues. Before listening to each one, you will have time to read the questions related to it. While listening, answer each question by choosing A, B, C or D. After listening, you will have time to read your answer. You will hear each piece once only.

Questions 11-13 are based on the following monologue. You now have 15 seconds to read Questions 11-13.

How did the fire start

A．A motorist carelessly threw out a lighted cigarette.
B．A man passed the forest and lit it on purpose.
C．The bushes and trees were so dry that they burned by themselves.
D．No one knew the cause.