Which of the following statements are true ?

A. Hot-rolled and hot-drawn products have a wider dimensional tolerances and rougher surface finish than cold-rolled and cold-drawn products.

B. Seamless tubing made by the tube-rolling process have more thickness variation than that of roll-formed and welded tubing.

C. Castings generally have higher dimensional accuracy and smoother surface finish than parts made by cold extrusion.

D. Extrusions have smaller cross-sectional dimensional tolerances than parts made by roll forming.