网页展示平面有限的情况下，折叠菜单是一个很不错的选择。这种菜单在一般情况下是折叠起来的，只有当浏览者将鼠标移动到菜单上时，菜单才会滑动展开。 -Page impressions planar limited circumstances, folding menu is a very good choice. This menu under normal circumstances is folded, and only when visitors mouse over the menu, the