Midwestern topsoil, some of the finest cropland in the world, is made up of loose, heterogeneous clumps with plenty of air pockets between them.是什么意思_Midwestern topsoil, some of the finest cropland in the world, is made up of loose, heterogeneous clumps with plenty of air pockets between them.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句