The first few lines retrieve the values from the drop-down list boxes in which the user selects usage and configuration, respectively.
前面几行代码分别从用户选择用法和配方的下拉列表框获取值。
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Lines 49 to 52 define the menu and MenuItem for the add, find, and clear actions, which can be accessed from drop-down menus when the application is deployed and run.