题目内容：
回答题：Every year landslides(滑坡)cause 25 to 50 deaths and$1．5 bnlion in damage in the UnitedStates．They account for l5 percent of the deatlls from natIlral disasters in Europe．And there waseVer a single event killed more mall 200 people in the Philippines．Sending workers to stabilizemountainsides using steel bars and cement(水泥)can help prevent disasterS’but it introductes newdimculties．shaking drills produce harmful dust and loosen heaVy，daJlgerous debris(岩屑)．“It’s quite a risky job，”says Giorgio Pezzuto of D’AppoloIlia，an engineering company in Italy．
D’Appolonia，worl(ing with eight omer compaIlies，may have an answer：a three-ton．robotcalled Roboclimber．“The idea is to operate a machine far away that can drill wimout a human be．ing on board，”says Pezzuto，me manager for me project，which is supponed by the EuropeanCommission．Engineers claim mat me machine will be faster and cheaper tllan manual labor.Therobot，a large radio—controlled four-legged mechanjcal spider，has cost at least$2 IIlimon So far.The final product should be able to climb unstable mountainsides，drill holes。insen bars and ce-ment，and coUect data on tlle stability．Testing should begin in May．
The underlined word“eVent”(Paragraph l)referS to__________． A．1andslide
B．machine
C．earthquake
D．nood
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