With a standard drop-down list, the user is limited to choices in the list, but with a combo box, the user can enter a value that is not in the list.

通过标准的下拉列表，用户只能够选择列表中的选项，但是如果使用组合框，那么用户就能够输入一个列表之外的值。

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You use this list to populate the drop-down combo box for the view against which your mail rules execute.

使用该列表来填充(对其执行邮件规则的)视图的下拉组合框。

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For example, one browser might show a select1 control as a pop-up menu or combo box while another might use radio buttons and a third a scrolling list.

比如，一种浏览器可能把select1显示成弹出菜单或者组合框，另一种浏览器则使用单选按钮，第三种则显示为滚动列表。

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