the tread grooves pass air between the tyre and road surface, thereby preventing tyre from overheating
the crests between the tread grooves absorb road noise
in wet conditions, the tread grooves expel water that is drawn between the tyre and road surface
the tread pattern protects the tyre's inner carcass from small stones and pieces of glass
heating rubber under pressure
spraying with special paint
melting rubber while stirring it
none of these
all plies run parallel to one another
belts of steel mesh are used in the tyres
one ply layer runs diagonally one way and another layer runs diagonally the other way
all of the above
steel
copper
zinc
aluminium