Use the alignment grid to align objects as you place them.
To align objects along axes after you place them, use the Align Objects pull-down menu on the toolbar or select Edit»Align Items. You can align an object along a horizontal axis using its top or bottom edge or its center point. You can align an object along a vertical axis using its left or right edge or its center point. The alignment option you select remains in effect until you change it. A dark border around the icon in the pull-down menu indicates the current alignment option.
Complete the following steps to align objects.
To repeat an alignment operation on another group of objects, press the <Ctrl-Shift-A> keys. (Mac OS) Press the <Command-Shift-A> keys. (Linux) Press the <Alt-Shift-A> keys.
You also can select Edit»Align Items to repeat an alignment operation on another group of objects.