词语

指掌可取掌：手掌。手掌里的东西随时可以取得。形容非常容易。

了如指掌形容对情况极为清楚。例对他们的活动他完全了如指掌。英have sth.at one’s fingertips; know as one know his ten fingers; know like a book; know as well as a beggar knows his bag;