关键词属于主题词中的一类，主题词除关键词外，还包含有单元词、标题词和叙词。关键词是标识文献的主题内容，单未经规范处理的主题词。 Tutorial assistance solutions furnished by Tutorial Saviour are intended for consulting and educational functions only. Any files and files that a purchaser receives from Educational Saviour really should be viewed as samples / drafts and are not purported to ... https://bookmark-group.com/story14340128/how-much-you-need-to-expect-you-ll-pay-for-a-good-%E8%AE%BA%E6%96%87%E4%BB%A3%E5%86%99