Howdidzebrasgettheirstripes?It’shardtogetablack-and-whi...
问题详情：Howdidzebrasgettheirstripes?It’shardtogetablack-and-whiteanswer.Somescientistssaythestripesareaformofcamouflage(伪装)，___61___ protectszebrasfromhungrylions.Otherssaythey’rekeytozebras’ma...