如果你并没有暴露在危险物中，就没有危险。

If something is a hazard for which are you not getting an exposure, there is no risk.

youdao

避开高大建筑物或构筑物避开危险物、高耸、悬挂物或其它危险物品。

Avoid tall buildings or structures to avoid hazards, tall, Xuangua Wu or other dangerous substances.

youdao

And also, it's useful because harmful stimuli are noticed but when something has shown itself to be part of the environment you don't notice it anymore.

而且它还是非常有用的,因为危险刺激会吸引到你的注意,但当某物被视为环境的一部分时,你便不会再去注意到该物体。

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