(a)        (i)         Sketch  a 4-speed sliding mesh gear arrangement with third speed                            engaged.
            (ii)        Show  the power path of the drive in the third gear.
                        (b)        Label the following parts of the sketch  in (a)(i):
              (i)         input  shaft;
              (ii)        main  shaft;
              (iii)       constantmesh gear;
              (iv)       lay  shaft.
                                    (c)        State  two demerits of sliding mesh gearbox.