Answer:
Oiling is done on a regular basis to sewing Machine because in the machine there are lots of machinery parts i.e. wheels and axels, etc. which are in continuous use and they possess so much frictional force between them that wear tear may be observed in those parts.
Answer:
dont get it wet or it wont work at all
Solar Energy: source Sun
Nuclear Energy: source:fission of Uranium nucleus
Sound Energy: source: Loudspeakers
Iron, aluminum, and silicon.
