单选题
Firefighters are often asked to speak to school and community groups about the importance of fire safety, particularly fire prevention and detection. Because smoke detectors reduce the risk of dying in a fire by half, firefighters often provide audiences with information on how to install these protective devices in their homes. Specifically, they tell them these things: A smoke detector should be placed on each floor of a home. While sleeping, people are in particular danger of an emergent fire, and there must be a detector outside each sleeping area. A good site for a detector would be 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 detectors 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. Detectors 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.
单选题
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
【正确答案】
D
【答案解析】[解析] 细节题目。文章首句提到，Firefighters are often asked to speak to community about the importance of fire safety，particularly fire prevention and detection．可知消防员要告诉居民防火知识。根据句子意思推出正确答案是D选项。
单选题
Compared with homes without smoke detectors, homes with them give their owners a 50% better chance of ______. A. surviving a fire B. preventing a fire C. detecting a hidden fire D. not getting injured in a fire
【正确答案】
A
【答案解析】[解析] 细节理解题目。文章第一段第二句提到，烟雾感应器在火灾中可以降低一半的死亡率。而A项surviving a fire的意思是在火灾中存活，二者的意思是一致的。所以正确的答案是A选项。
单选题
A smoke detector must always be placed ______. A. on any level of a home B. outside all bedrooms in a home C. in all hallways of a home D. in kitchens where fires are most likely to start
【正确答案】
B
【答案解析】[解析] 推理题。文章第二段提到，there must be a detector outside each sleeping area．意思是卧室外要安装烟感，这里的each和B选项中的all是一个意思。据此可以推出正确答案是B选项。
单选题
The passage implies that dead-air space is most likely to be found ______. A. on a ceiling four inches away from a wall B. near an open window C. close to where a wall meets a ceiling D. in kitchens and garages
单选题
What is the focus of this passage? A. How firefighters carry out their responsibilities. B. The proper installation of home smoke detectors. C. The detection of dead-air space on walls and ceilings. D. How smoke detectors prevent fires in homes.