An access key also known as a mnemonic is an underlined character in the text of a menu menu item label of a button or some other control .

访问键（也称助记键）是菜单、菜单项、按钮标签或其他某控件的文本中 带 下划线 的 字符。

Tom pushed the book towards me and asked how to read the underlined character .

汤姆把书推到我面前问我 划线 的 字怎么读。