知识扩展
习语积累
习语 n. have sth at your fingertips 掌握（信息等）；熟悉，精通（知识等）；对…了如指掌；有…随时可供使用 to have the information, knowledge, etc. that is needed in a particular situation and be able to find it easily and use it quickly to your fingertips (BrE) 完全；十足 in every way She's a perfectionist to her fingertips. 她是个道道地地的完美主义者。
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