Correct 复线 / fùxiàn / Strokes Definition multiple track (e.g. rail)/multi-lane (e.g. highway)/the complex line (math.) Example As a Noun double/dual track; multiple track 复线 - Chinese Dictionary Definition multiple track (e.g. rail)/multi-lane (e.g. highway)/the complex line (math.) multiple track (e.g. rail)/multi-lane (e.g. highway)/the complex line (math.)