Read and classify. 请把下列单词归类。

my      three     pencil     board     her      red       his      your    four     

green   blue      eraser     seven     eight   paper    yellow

物主代词：                                                                                

学习用品：                                                                                

数字：                                                                                       

颜色：                                                                                       

消极型管理是弱效市场的最佳选择。( )