我知道有很多话题都在讨论这个问题，但我无法弄清楚我的实现过程中出了什么问题。我有以下文件:{"_id":ObjectId("510a353929e16756d5000009"),"skills":[["UserEmbed::Author::Skills::Copywriting","UserEmbed::Author::Skills::Proofreading","UserEmbed::Author::Skills::Proofreading","UserEmbed::Author::Skills::Translation","UserEmbed::Author::Skills::Tr