简介：美国画家托马斯·莫兰随探险队历经千辛闯入西部的巍峨峡谷，创作出了一幅恢弘的画卷。正是这幅巨作催生了关国第一个国家公园——黄石公园。

简介：Nowadays,cannabishasbecomethemostprevalentusingdruginmostWesterncountries.WithCanadabecomethesecondcountryfollowingUruguaytolegalizerecreationalcannabisusing,cannabislegalizationislikelytobecomethetrendinWesternworld.ThoughbothUruguayandCanada,aswellasthestatesintheU.S.thatlegalizedrecreationalcannabisusinghavetheagerestriction,arecentresearchindicatedthatcannabisusingisspreadamongteenagers.WithregardtothewidespreaduseofcannabisandthelegalizationofrecreationalcannabisusinginCanadaandsomestatesoftheU.S.,thisstudyfocusesontheeffectsofthelegalizationofcannabisusingamongteenagerstoexplorethereasonswhyteenagersusecannabis,whycannabiscanbelegalized,andwhateffectsthelegalizationofcannabismayhaveonteenagers.

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