lens tube

例句：

1. 1. The lens tube is the part of the camera that focuses light onto the film.
   镜头管是相机中将光线聚焦到胶片上的部分。
2. 2. The lens tube is made of glass and can be used to focus light from a flash.
   镜头管由玻璃制成，可用于聚焦闪光灯的光线。
3. 3. The lens tube is essential for taking clear photos with a telephoto lens.
   镜头管对于使用长焦镜头拍摄清晰照片至关重要。