duality

n. 二元性

dry ice, dry land, dry measure, dry rot, dry run, dry up, dry-clean, dry-nurse, dry-shod, dry-walling, drying, dryness, drystone, DSc, DSO, DT, dual, dual carriageway, dual-control, dual-purpose, dub, dubbin, dubiety, dubious, ducal, duchess, duchy, duck, duck-boards, duck-yard, ducking, duckling, ducks and drakes, duckweed, duct, ductile, ductility, ductless gland, dud, dude,