Californiahaslosthalfitsbigtreessincethe1930s,according...
问题详情：Californiahaslosthalfitsbigtreessincethe1930s,accordingtoastudytobepublishedTuesdayandclimatechangeseemstobeamajorfactor（因素）.Thenumberoftreeslargerthantwofeetacrosshasdeclinedby50percentonmore...