Select the correct matching:

Which alloy contains $Cu$,$Sn$,and $Zn$?

One of the constituents of German silver is:

The advantage$(s)$ of using $O_2$ rather than air in the steel industry is(are):
$(I)$ There is a faster conversion,so a given plant can produce more steel in a day.
$(II)$ Larger quantities can be handled.
$(III)$ It gives a purer product,and the surface is free from nitrides.

Match the alloys in Column $A$ with their uses in Column $B$:

Column $A$	Column $B$
$(1)$ Stainless steel	$(a)$ Riveting
$(2)$ Bronze	$(b)$ Making artifacts
$(3)$ Nitinol	$(c)$ Making coins
$(4)$ German silver	$(d)$ Making musical instruments
	$(e)$ Making surgical instruments

Copper matte is composed of . . . . . .