1、
a ring r is left perfect (right perfect). each of its left (right) modules has a projective cover.
环R是左（右）完全环，是指任意的左（右）R-模有投射盖。
互联网摘选
a ring r is left perfect (right perfect). each of its left (right) modules has a projective cover.
环R是左（右）完全环，是指任意的左（右）R-模有投射盖。
互联网摘选
英语网英语词典(dict.25820.com)为您提供在线翻译、英语词典、单词大全、英译汉、汉译英等英语服务！可按单词头尾、字数和词义分类查询。支持lj:关键词格式查询例句。
