Unit 5 Into the unknown预习新知早知道预习新知早知道upwards investigationmillimetresubstancedrillingvolumefurthermorethink twiceinvestigationset outshrink fromsubstancelook intosteer clear ofthrow yourself intounknownnotableinvestigationlimited detailedcuriosityexplorationnatural大约有三百万艘沉船比我们地球自更详细的己的海床(地图)还要详细就像是完全出自科幻小说相当于50架飞机层层叠加保持了载人潜水艇最深潜水的纪录