Because they are cheaper to make. If you look for quality you would choose the metal articles.
Some clocks are made of plastic but not all of them are, they can be made from wood and metals too.
Plastic, and various metals.
they are made of metals and plastic
Most toy aeroplanes are made from plastic. Real planes are made from various metals.
Metals, plastic, and glass.
Switches are made of plastic or bakelite because they don't conduct electricity.
Wood, Metals or Plastic, usually.
because plastic melts on heating and metal doesnot melt on heating.metals are good conductors of heat.
Metals, plastic, maybe even a wooden handle.
metals are good conductors of electricity. plastic and wood are insulators. they do not conduct electricity
The casings are made of plastic, the inside cantains some metals and circuitboards
Dust bins or garbage bins are made of steel or plastic