这是可以任选的功能部件。

This is an optional feature.

youdao

毯子和枕头(任选的)。

Blanket and pillow (optional).

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上午您可以随意消闲，也可以参加任选的半日出游活动。

Morning at your leisure or optional half day tour in the morning.

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So the strategy choices, we're not going to do it in hours, let's just normalize and regard these choices as living in 0 to 4, and you can choose any number of hours between 0 and 4.

我们用小时数来表示策略吧,用0到4的数字来标记这些策略,你可以从0到4中任选工作的小时数

耶鲁公开课 - 博弈论课程节选