Treesareusefultomaninthreeimportantways:theygivehimwood...
问题详情：Treesareusefultomaninthreeimportantways:theygivehimwoodandotherusefulthings,theygivehimcoolplaces,andtheyhelptostopdroughtandflood.Unluckily,inmanypartsoftheworld,manhasnotfoundthatthethirdoft...