You can examine the list of past operations and select some operation in the list to Undo; however, you are not undoing that one operation, but rather all operations back to that point, inclusive (see Figure 16-1).

• 你可以检查过去操作的列表，并且在列表中选择一些操作进行撤销。 然而你不是撤销一次操作，而是使所有操作返回原来的状态（见图16-1）。