11) What is the process of surface smoothened by rubbing with sand paper or pumic stone for varnishing?

12) What is the term used for the pores on the surface are filled up with boiled linseed oil?

13) Which metal has content of aluminium alloy 94% copper 4%?

14) What for the corrugated sheet form of steel in mostly used?

15) Which stone joint is used in arch work?