Specifically, they tell them these things: A smoke detector should be placcd on each floor of a home. While sleeping, people are in particular danger of an emergent fire、 and there must he a dctcctor outside each sleeping area. A good site for a detecior would he a hallway that runs between living spaces and bedrooms.
Because of the dead-air space that might be missed by hot air bouncing around above a fire, smoke detcctors should be installed either on the ceiling at least four inches from the nearest wall, or high on a wall at least four, but no further than twelve, inches from the ceiling.
Deteccors should not be mounted near windows, entrances, or other places where drafts (过堂风) might direct the smoke away from the unit. Nor should they be placed in kitchens and garages, where cooking and gas fumes are likely to cause false alarms.
One responsibility of a firefighter is to______.

A. install smoke detectors in residents homes
B. check if smoke detectors are properly installed
C. develop fire safety programs for schools
D. speak to residents about how to prevent fires