Arrow tool 
Arrow tool performs a number of different functions. We discuss each function separately.
Arrow tool as a selection tool
When we need to edit a portion or complete object we must select that portion to point
out which portion is being modified because FLASH doesn't know which portion of image
you want to change. To do so we select it by "arrow tool".
Choose "arrow tool" from the tool bar and click on the object.
Selected object is highlighted as shown below:
Original object Selected object
Partial selection of an object
When you need to select a small or large portion of an object, drag your cursor from out side the object to inside assuming that you are drawing an imaginary rectangle. 
Select "arrow tool".Place cursor at point 1,drag to point 2 then drag to point 3 and release mouse(see below).
Notice that half of the circle is selected.
Select any portion of object by arrow tool and press "delete".
original image 
  selected portion 
After trimming
Arrow tool as a move tool
With the help of arrow tool we can move an object from one point to any other point.
Choose arrow tool. Place cursor over the object,click and drag object to a new position.