题目内容：
根据以下材料回答题 Everyyearlandslides(滑坡)cause25to50deathsand$1.5billionindamageintheUnitedStates．Theyaccountfor15percentofthedeathsfromnaturaldisastersinEurope．Andtherewaseverasingleeventkilledmorethan200peopleinthePhilippines．Sendingworkerstostabilizemountainsidesusingsteelbarsandcement(水泥)canhelppreventdisasters,butitintroducesnewdifficulties．Shakingdrillsproduceharmfuldustandloosenheavy,dangerousdebris(岩屑).
"It'squiteariskyjob,"saysGiorgioPezzutoofD'Appolonia,anengineeringcompanyinItaly.D'Appolonia,workingwitheightothercompanies,mayhaveananswer:athree-tonrobotcalledRoboclimber．"Theideaistooperateamachinefarawaythatcandrillwithoutahumanbe-ingonboard,"saysPezzuto,themanagerfortheproject,whichissupportedbytheEuropeanCommission．Engineersclaimthatthemachinewillbefasterandcheaperthanmanuallabor．Therobot,alargeradio-controlledfour-leggedmechanicalspider,hascostatleast$2millionsofar.
Thefinalproductshouldbeabletoclimbunstablemountainsides,drillholes,insertbarsandce-ment,andcollectdataonthestability．TestingshouldbegininMay.
Theunderlinedword"event"(Paragraph1)refersto__________. A．landslide
B．machine
C．earthquake
D．flood
参考答案：
答案解析：