Answer:
Friction is needed
° you walk on a slipper road
° the book on the table should not slip
° your parents slows down the car
° you write on a sheet of paper
° you walk on the floor
Friction should be reduced
° heat is produced in various parts of machines
° engines of vehicles consume more fuel
° door hinges become rusty
° noise is produced in machines
° an object needs to move fast
