These are: International Airlines Group (BA and Iberia) plus American Airlines; United, including Continental, and Lufthansa and Air Canada; and Air France-KLM with Delta, incorporating Northwest.

它们是：国际航空集团（BA和伊比利亚）加上美国航空；联合航空，它包括大陆航空、德国汉莎和加拿大航空；法航-荷航与合并了西北航空的达美航空。

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Companies that use a plus-delta model of understanding what customers love (the plus) and what they would improve (the delta) make improvements to their operations quickly and efficiently.

公司使用敏感性分析模型去了解消费者喜欢什么(用加号)和他们需要改进什么(用三角形)，这样可以更快更有效率的改进他们的运营。

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When the data has just been moved into that table, it contains in our scenario information that is no more than an hour old, plus a small delta corresponding to the time required to execute the step.

在本场景中，当数据刚刚被移到该表中时，它包含的信息要少于一个小时的，因为执行该步骤所需的时间导致了很小的时间差量。

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This is delta minus and this is delta plus.

这边是负电，这边是正电。

麻省理工公开课 - 固态化学导论课程节选

You can use delta minus, delta plus.

你可以用△+，△

麻省理工公开课 - 固态化学导论课程节选

U OK, so let's look at delta u. Delta u is q plus w.

好的，让我们看看Δ

麻省理工公开课 - 热力学与动力学课程节选

There are three major frequent flyer alliances that bring together the loyalty programs from several different airlines: Star Alliance (United, Continental, US Airways, Lufthansa, Singapore Airlines, and 21 more), One World (American Airlines, British Airways, Iberia, and nine others) and Sky Team (Delta, Air France, KLM, plus 10 more).

BBC: Insider flight tips from a seasoned business traveller

Unlike Delta's product, United's economy plus option is on both domestic and international fleets.

BBC: Flying in the fourth class

After you have torn up its 120-plus runs, warm up in the Delta's heated outdoor pool with indoor entrance, three outdoor hot tubs and a sauna.

BBC: Daily deal: Canadian mountain lodge