This time, the intervening operation was not the insignificant single-word deletion of the earlier example. The intervening operation was complex and difficult and having to Undo it is clearly an unpleasant, excise effort.

• 这次的介入操作不像先前删除一个单词的例子，这个介入操作复杂而困难，并且撤销它明显是让人很不愉快的附加工作。