Light sent into the oil layer was confined there, bouncing between the metal and air boundaries. The beam spread out ever more quickly, generating a trumpet-shaped glow (see image).

当把光传入油层后，就被约束在那里，光线在金属和空气的边界之间不断反弹，于是产生了喇叭状的辉光(见图片)。

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The beam does not spread out appreciably, even at large distance from the source.

它的光束，即使离光源极远，也不显著扩散。

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Fache backed away from the body and raised the black light again, letting the beam spread out in a wider Angle.

法希从尸体旁向后退了退身，再次高举起黑光灯，使光线从更大的角度散发出来。

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