[听力原文]
W: The party starts at 7:30. We can leave the house by 7:15.
M: But I suggest we leave at 7:00. You know how bad the traffic is that time of night.

When will they leave（）

A．a text book
B．a science fiction
C．a popular magazine
D．a report of a manufacturer

A．accidents mostly result from slippery roads
B．accidents are usually caused by psychological factors
C．doctors run three times the normal risk of accidents in factories
D．about 50,000 people lose their lives at work in Britain every day