题目

下列关于传感器的说法中正确的是()A. 电子秤应用的是光传感器B. 电饭锅通过温度传感器实现温度的自动控制C. 干簧管是一种能够感知电场的传感器D. 霍尔元件能够把电学量转换为磁学量 答案：【答案】B【解析】电子秤应用的是压力传感器，选项A错误；电饭锅通过温度传感器实现温度的自动控制，选项B正确；干簧管是一种能够感知磁场的传感器，选项C错误；霍尔元件能够把磁学量转换为电学量，故D错误。故选B.Escaping a fire is a serious matter. Hundreds of people are killed because of fire every year. Knowing what to do during a fire can save your life. It is important to know the ways you can use and show them to everyone in the family, such as stairways or windows escapes, but not elevators. From the lower floors of the buildings,    62     . it is the best way of leaving by windows with the least chance of serious injury. The second floor window is usually not very high from the ground. A middle build person, hanging by the fingertips will have a drop of about six feet to the ground,     63     .Of course, it is safer to jump a short way than to stay in a burning building. Windows are also useful when you are waiting for help. Be sure to keep the door closed,      64     __. Keep our head low at the window to be sure you get fresh air rather than smoke that may leak into the room. A. From the roof a person can drop to the ground more safely. B. escaping through windows is possible. C. or smoke and fire may be drawn into the room. D. it is about the height of a middle build man. On a second or third floor, the best windows for escape are those that open onto a roof.        65     .Dropping onto cement（水泥） might end in injury. Bushes and grass can help to break a fall.