Something bad or unexpected can happen when people send up a self-controlled flying machine like a drone without knowing how to really control it.

当人们在不知道如何真正控制它的情况下发射一个像无人机一样的自我控制飞行机器时，可能会发生一些糟糕或意想不到的事情。

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Is the event unusual or unexpected?

该事件是否不寻常或意外？

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unusual or unexpected nature of the event;

事件性质的不寻常或意外；

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Examples include large medical bills, the loss of financial aid or an unexpected change in the financial condition of their source of support.

VOA: special.2009.01.29

Were there kinks that had to be worked out, or unexpected problems that arose?

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When the market makes an unexpected breakout or unexpected movement, then psychology plays an important role.

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However, that assessment by the Fed chief is certainly nothing new or unexpected.

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