A:She is wearing an old shirt.
B:He is wearing an old shirt.
C:He is wearing an old sweater.
谨食之,时而献焉。退而甘食其土之有,以尽吾齿。盖一岁之犯死者二焉;其余,则熙熙而乐。岂若吾乡邻之旦旦有是哉!
作者写蒋氏这番话,主要是为了说明( )
读“东西半球分布图”(如图),关于世界海陆分布的叙述,正确的是( )