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.

　　答案與題解：

　　1. D 短文第一段的第一句告訴我們，英國研究人員正在測試一種儀器，這種儀器可以通過監(jiān)測土壤的振動來預(yù)警山崩。該段最后一句說，這種災(zāi)難經(jīng)常在一些遭受自然災(zāi)害的國家發(fā)生，這些自然災(zāi)害包括sudden，heavy rainfall和earthquakes以及water erosion.所以D是正確選擇。

　　2. D A、B、C的內(nèi)容都可在第二段中找到。所以D是正確答案。

　　3. C 第三段的第一和第二句告訴我們，最為普通的監(jiān)測山崩方法是對山坡形狀變化的觀察，有兩種觀察方式；第三句說，因為山坡形狀的變化不一定導(dǎo)致山崩，所以兩種方法都會有虛假的預(yù)警。因此，C是正確答案。

　　4. A B、C、D所述內(nèi)容都可在第四段中找到。The borehole is filled in with gravel around the pipe.在被鑿出的洞里填充沙礫，圍在鋼管四周。不是在鋼管里填充沙礫。所以A是錯誤的說法，是正確的選擇。

　　5. B positives在此用作名詞，意思是：被證實的因素或特點，可以理解為證據(jù)。