sandpaper

n [U] strong paper coated with sand or a similar substance, used for rubbing surfaces smooth 砂纸. v [Tn, Tn.p] smooth (sth) with sandpaper 用砂纸磨光（某物）.

sanctity, sanctuary, sanctum, sand, sand trap, sand-bar, sand-blast, sand-castle, sand-dune, sand-fly, sand-pit, sand-shoes, sand-yacht, sandal, sandalled, sandalwood, sandbag, sandbank, sandboy, sandiness, sandpiper, sands, sandstone, sandstorm, sandwich, sandwich board, sandwich course, sandy, sane, sanely, sang, sang-froid, sangria, sanguinary, sanguine, sanguinely, sanguineness, sanitarium, sanitorium, sanitary, sanitary towel, `sanitary pad,