水平居中
水平居中对齐选中的对象。如果在 Draw 或 Impress 中只选择了一个对象，则将该对象的中心与页面的水平中心对齐。
The vertical position of the selected objects is not affected by this command.
To align the individual objects in a group, choose to enter the group, select the objects, right-click, and then choose an alignment option.
To align the individual objects in a group, double-click to enter the group, select the objects, right-click, and then choose an alignment option.