这些方块使用两个相连的字母标识：第一个字母表示经度区的东西位置，而第二个字母表示南北位置。

These squares are identified by two-letter digraphs: the first letter is the east-west position within the longitude zone and the second letter is the north-south position.

youdao

当我关上它的时候，我看不到那个方块的确切位置。

Off, I couldn't see where the block really was.

youdao

我用的是暗方块的方式式作为参考，以便找到合适的位置，这一层。

I used the darker square from pattern as reference in order to find the right position for this layer.

youdao