Because they have three options.

因为他们有三个选择。

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Now students have to have a flexible outlook with two or three viable options that they pursue aggressively.

现在，学生不得不设定一个相对灵活的前景展望，拥有两个或者三个可行的选择，以使他们能够进行更积极主动的追求。

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Until they reach a consensus, you have three options for obtaining vitamin D: food, sunlight, or supplements.

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Canadians have had fairly limited options for LTE-based 4G if they didn't want to turn to the three main carrier brands: they could go to a Bell-owned Virgin Mobile, and that's it.

ENGADGET: Fido switches on LTE, gives Canadians a taste of slightly more budget-minded 4G