Aligns the endpoints
            of curves.
         
         
         Edit Curves > Align
                  Curves >   
 
            
            - Attach
- 
                  Joins
                        the curves. If you turn this option on, turn Construction
                           History off or the curve might deform oddly when you
                        transform it.
                      
- Multiple Knots
- 
                  Keep creates
                        multiple knots at the attached region, which lets you break the
                        curvature continuity there.
                      Remove deletes
                        as many knots as possible without changing the shape of the attached region.
                      
- Continuity
- 
                  Select
                        how the curvature at the end of two points meet.
                      Position causes
                        the two points to meet exactly. 
                      Tangent causes
                        the tangency at the two points to match.
                      Curvature causes
                        the two points to meet with the same arch in curvature. When this
                        option is selected, the curvature scale sliders are available.
                      
- Modify Position
- 
                  Select
                        how the curves will be positioned.
                      First moves
                        the entire first curve to the second curve.
                      Second moves
                        the entire second curve to the first curve.
                      Both moves
                        both curves halfway.
                      
- Modify Boundary
- 
                  Select
                        the boundary of the curves will be positioned.
                      First moves
                        the selected point of the first curve to the second curve.
                      Second moves
                        the selected point of the second curve to the first curve.
                      Both moves
                        the selected points of both curves halfway.
                      
- Modify Tangent
- 
                  Select
                        which curve’s tangent to modify.
                      First adjusts
                        the tangent of the first curve selected.
                      Second adjusts
                        the tangent of the second curve selected.
                      
- Tangent Scale First
                        and Second
- 
                  Select
                        which curve’s tangent to modify.
                      First increases
                        or decreases the tangent magnitude of the first curve selected.
                      Second increases
                        or decreases the tangent magnitude of the second curve selected.
                      
- Curvature Scale First and
                        Second
- 
                  Select
                        which curve’s curvature to modify.
                      First increases
                        or decreases the curvature of the first curve selected.
                      Second increases
                        or decreases the curvature of the second curve selected.
                      
- Keep Original
- 
                  Retains
                        the original curves and aligns copies of the curves.