After switching on powerful arc lights.

他们打开强力弧光灯。

After switching on powerful arc lights, they saw great stalagmites.

他们打开强力弧光灯，看见一株株巨大的石笋。

The arc lights were sputtering overhead, and high up were the lighted Windows of the tall office buildings.

弧光灯在头顶上方闪烁。更高处，写字楼的窗子里透出光明。

The arc lights were sputtering overhead , and high up were the lighted windows of the tall office buildings.

弧光灯在头顶上方闪烁。更高处，写字楼的窗子里透出光明。

After switching on powerful arc lights, they saw great stalagmites — some of them over forty feet high — rising up like tree-trunks to meet the stalactites suspended from the roof.

他们打开强力弧光灯，看见一株株巨大的石笋，有的高达40英尺，象树干似的向上长着，与洞顶悬挂下来的钟乳石相接。

Indoors light is furnished by carbon arc lamps incandescent bulbs and quartz bulbs. the basic indoor lights are spotlights and floodlights. spotlights throw a beam of concentrated intense light.

室内光源有碳弧光灯，白炽灯及石英灯等。室内的主光源是聚光灯和散光灯、泛光灯。聚光灯将光聚到一起。

The Grand Theater is just like a crystal palace when the lights set off a harmonious entity of the white arc-shaped roof and the photosensitive glass curtain walls.

白色弧形拱顶和具有光感的玻璃幕墙有机结合，在灯光的烘托下，宛如一个水晶般的宫殿。

In the video below, the lights appear to be blinking continuously, but that's an effect of the camera - human eyes would see it as forward-moving solid arc of light.

在下面的视频中，车灯看上去在不停闪烁，但这实际上是由于照相机的缘故——人眼会看到顺时针旋转的光弧。