switch-level modeling交换: exchange; swap; interchange; ...层次: administrative levels的: 4次方是 The fourth power of 2 i ...模型: model; pattern交换层: switching layer下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:交换层次的模型，即可在微信中查询翻译
