beam supported at both ends

例句：

1. 1. The beam of light from the lamp illuminated the room.
   灯的光柱照亮了房间。
2. 2. The beams of sunlight were shining through the window.
   阳光透过窗户照射进来。
3. 3. The beam of a spotlight is used to highlight an important point.
   聚光灯的光束用于突出重要点。