A lot of pilots are qualified to fly developmental test but they might not have the Weapons School credential that allows Air Combat Command to trust their opinions more easily.

也有许多飞行员可以飞研发试飞，但他们可能没有武器学校的文凭来使空战司令部更轻松地认可他们的选择。

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Children’s main job is to figure out how their complex world works. In order to master the things they need to at each developmental level they will test their parents.

孩子会主动学习这个复杂世界的法则，在不同的发育阶段，他们都会为作出各种尝试，以了解这些法则。

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"The reason we call them test flights or developmental flights is because if you know it is going to work, it's not a test, " he said.

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The makers told us that these were the developmental models, and admittedly, our second test device was far more stable.

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