To clear your media pool of all un-used clips click on the previously mentioned lighting strike button.

若要清除媒体池中所有未被使用到的媒体文件，只需点击前文提到过的“闪电”按钮即可。

All the practice shows, the measures can protect the architecture and equipment of the cement plant from damage of lighting strike.

实践证明，这些措施可有效保护水泥厂的建筑结构和设备遭受雷击破坏。

Finding the right lighting direction requires the photographer to strike a balance between several potentially competing considerations.

找到合适的光源的方向需要摄影师之间找到平衡点几个潜在的竞争的考量。