By default, as long as you have not selected any other entry, the arrow buttons jump to the previous or the next page in the document. The arrow buttons are black if you are browsing through pages and blue if you jump to other objects.
在没有选中任何一个条目的情况下，单击这个图标，程序预设光标跳跃至上一页或下一页。在您浏览页面时，两个双箭头图标的颜色是黑色的，输入光标跳跃至某一个文档对象时，箭头颜色就会变成蓝色。