Haveyoueverheardofan的精选

问题详情：Haveyoueverheardofaninsectcalledthecicada(蝉)?36 Buttheyhaveaninterestinginternalclockthattellsthemwhentogoaboveground.Every17years,billionsofthenoisyBroodVcicadas(十七年蝉)willswarm(成群出现...