桌面上有几个小凹痕，可能是被钥匙压出来的。

There are several small ___indentations on the desk surface, probably made by keys.

在Python代码中，缩进非常重要，因为它们决定了代码块的层次关系。

In Python code, ___indentations are crucial as they define the hierarchy of code blocks.

月球表面有许多由陨石撞击形成的凹坑。

The moon's surface has many ___indentations caused by meteorite impacts.