a reinvent and beaches is a mean of hard implement & a bicycle is made of levers, wheels and axles, pulleys, and screws & a screw is a kind of simple machine & a pulley is a kind of simple machine & a lever is a kind of simple machine ->  a bicycle is made of more than one simple machines  a young is made of more than zero hard turning & a complex machine is made of more than one simple machine -> a bicycle is a kind of complex machine