八年级语文期末考试题及答案-frank的日志-网易博(12)

affected by field noise, slow detection speed and so on.

The radar life detector is mainly made using the reflection principle of electromagnetic wave・ The radar signal transmitter continuously transmits electromagnetic signals and scans a certain space・ The receiver continuously receives the reflected signals and processes the return signals・ Because the frequency of breathing is low, usually 1 to 2 times per second, so breathing movements can be distinguished from other higher frequency movements・ It can detect the movement and respiration of trapped people within 30 seconds, and can penetrate obstacles (such as reinforced concrete brick wall, snow, etc・)to detect・Radar life detector is currently the world，s most advanced life detection instrument, detection means it active makes it not easily influenced by temperature, humidity, noise, site topography and other unfavorable factors, the continuous emission mechanism of electromagnetic signals increased its regional detection function. Compared with the infrared and audio detection technology, radar detection technology has more extensive application prospects, radar life detector will play a greater role・

13."radar life detector is the latest and most advanced life detection instrument in the wor 1 d〃・In this sentence, can the word "current" be deleted? Why?

14."it can detect the movement and respiration of trapped people within 30 seconds・"the method described in this paper highlights

15.in the 〃5? 12〃Sichuan earthquake disaster relief, China's rescue team may be the main use of what kind of life detector? Please combine