A.35° B.40° C.45° D.50°
A.10° B.15° C.20° D.25°
A.滑板箱、滑板和刀架 B.滑板箱、中滑板和刀架 C.滑板箱、絲杠和刀架 D.滑板箱、滑板和導(dǎo)軌