3. Why do researchers develop a new device to monitor signs of landsides？
A Because the new device can measure the site directly.
B Because the new device can be sunk into boreholes or fixed above ground.
C Because the common methods can cause false alarms.
D Because the common methods are useless.
4. Which of the following statements is NOT true of the device，according 1o Paragraph4？
A It is filled in with gravel.
B It consists of a steel pipe.
C It is dropped into a horehole filled in with gravel.
D It is connected to a sensor on the surface.
5. According to the context，what does the word “positives” in the fifth paragraph mean？
A Positive electric charges.
B Evidences.
C Warnings.
D Predictions.
答案与题解：
1. D 短文第一段的第一句告诉我们，英国研究人员正在测试一种仪器，这种仪器可以通过监测土壤的振动来预警山崩。该段最后一句说，这种灾难经常在一些遭受自然灾害的国家发生，这些自然灾害包括sudden，heavy rainfall和earthquakes以及water erosion.所以D是正确选择。
2. D A、B、C的内容都可在第二段中找到。所以D是正确答案。
3. C 第三段的第一和第二句告诉我们，最为普通的监测山崩方法是对山坡形状变化的观察，有两种观察方式；第三句说，因为山坡形状的变化不一定导致山崩，所以两种方法都会有虚假的预警。因此，C是正确答案。
4. A B、C、D所述内容都可在第四段中找到。The borehole is filled in with gravel around the pipe.在被凿出的洞里填充沙砾，围在钢管四周。不是在钢管里填充沙砾。所以A是错误的说法，是正确的选择。
5. B positives在此用作名词，意思是：被证实的因素或特点，可以理解为证据。