参考答案：three

解析：[听力原文] 1-4
W: Did you hear the story on the news this morning about the apartment fire down the street
M: I heard something about it. What happened exactly
W: A fire started about 3 o’clock in the morning in an apartment complex with about twenty apartments. One of the apartments was completely destroyed, and several of the others were damaged.
M: Do they know how the fire started
W: They’re not sure at this point, but they believe that it was started by someone smoking in bed. It’s a shame that one careless person can cause so much trauma for others, not to mention the thousands and thousands of dollars of damage.
M: Even more serious than the damage to property is the harm to the apartment’s occupants. I hear that several residents were rushed to the hospital, but at least none of them died.
W: It’s all so frightening. Do you know of anything I can do to keep this from happening to me
M: I guess the best thing to protect yourself is to make sure that you have a smoke alarm and a fire extinguisher in good working condition. The smoke alarm will give you an early warning that a fire has started, so you can call the fire department. If it is a small fire, maybe you can use the fire extinguisher to help put out the fire before the fire trucks arrive.
W: That’s good advice. ! think I’ll go home and check my smoke alarm.