to cross the line; to go too far
to draw a line (between); to make a distinction (between); to distinguish (between)
the front (of a battlefield); forefront
to draw a line (between); to make a distinction (between); to distinguish (between)
to draw the line; to set a boundary; to make a clear distinction
(running) abreast; side-by-side; in a row; neck and neck; (almost) equal
top notch; first rate; top-of-the-line; leading