The pivot row must be selected so that all the other basic variables remain positive.

必须选择枢轴行，以便所有其他基本变量保持正数。

youdao

Finally, the installation path must be selected.

最后，必须选择安装路径。

youdao

In certain situations services must be selected at runtime from a set of services based on QoS.

在某些环境下，必须在运行时从基于QoS的服务集中选择服务。

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Recordings selected for the registry must be at least ten years old.

VOA: special.2010.07.09

The arugula must be selected and handled with care, so that not a single leaf is wilted or bruised.

WSJ: Eric Ripert's Artichoke, Fennel and Arugula Salad

The GOP maintained that, under New Jersey law, Democrats missed the deadline for replacing a candidate, saying a candidate who wants to get off the ballot must do so at least 51 days before the election, and a replacement must be selected at least 48 days before the vote.

CNN: Supreme Court won't intervene in N.J. case

Still, the pre-buy facility must be judiciously selected and the inspection must be carefully monitored in person.

FORBES: What's The Best Jet For You? (Part 3)