Its narrow beam traveled from black trunk to black trunk, illuminating the ground.

这道窄窄的光柱在漆黑的树干间来回移动，照亮了下面的土地。

She illuminated her wand and directed its narrow beam across the path.

她把魔杖点亮了，用那道狭窄的光柱照着小路。

They narrowed the beam and they can actually stun and in some cases kill smaller prey.

它们把声波束变窄，就真的能够击晕有时甚至能杀死较小的猎物。

Its narrow beam traveled from black trunk to black trunk, illuminating the ground. And then it fell upon a pair of feet.

这道窄窄的光柱在漆黑的树干间来回移动，照亮了下面的土地，然后落在一双脚上。

She says: You end up with a very strong, narrow beam of light.

她说：你最终会得到一束非常强的窄光束。

Ron and Hermione raised their wands high enough to spread the narrow beams of light farther on the ground; Harry looked all around him, but his wand was nowhere to be seen.

罗恩和赫敏把他们的魔杖高高举起，让细长的光柱照亮更多的地方。哈利在周围找了又找，可是怎么也找不到他的魔杖。

So after many times in between the two mirrors, and many reflections passing through the crystal, you end up with a very strong, narrow beam of light that is just one colour.

因此，在两面镜子之间经过多次反射，多次反射穿过晶体后， 你最终会得到一束非常强、很窄的光束，它只是一种颜色。