职称英语理工类B级阅读理解精华练习(12)

　　Listening Device Provides Landslide Early WarningA device that provides earlywarning of a landslide by monitoring vibrations in soil is being tested by UKresearchers. The device could save thousands of lives each year by warning whenan area should be evacuated, the scientists say. Such natural disasters arccommon in countries that experience sudden, heavy rainfall, and can also betriggered by earthquakes and even water erosion. 　　Themost common way to monitor a slope for signs of an imminent landslide is towatch for changes in its shape. Surveyors can do this by measuring asidedirectly, or sensors sunk into boreholes or fixed above ground can be used tomonitor the shape of a slope. Slopes can. however, change shape withouttriggering a landslide, so either method is prone to causing false alarms. NowDixons team has developed a device that listens for the vibrations caused whenparticles begin moving within a slope. 　　The device is currently being testedin a 6-metre-tall artificial clay embankment in Newcastle2, UK. Early resultssuggest it should provide fewer false positives than existing systems. Once ithas been carefully and thoroughly tested, the device could be used to create acomplete early-warning system for dangerous Slopes. 　　What does Such natural disasters in the first paragraph referto? 　　B Earthquakes. 　　D Landslides. 　　A The initial movement is hard to spot. 　　C They can bedestructive in a matter of hours or minutes. 　　Why do researchers develop a new device to monitor signs of landsides? 　　B Because the newdevice can be sunk into boreholes or fixed above ground. 　　D Because the common methods areuseless. 　　A It is filled in with gravel. 　　C It is dropped into a borehole filled in withgravel. 　　According tothe context, what does the word positives in the fifth paragraph mean? 　　B Evidences. 　　DPredictions.