孔洞

A brown background is shown covered with a gray topping that has many holes. On the upper right, there is a deep hole in the brown background. In this hole is more gray topping. Please see the explanation for more detailed information.
画面显示的是一个棕色背景，上面覆盖着带有许多孔洞的灰色覆盖层。在画面右上方，棕色背景中有一个较深的孔洞，孔洞中也填有灰色覆盖层。有关更多详细信息，请参阅说明。