a treadmill is a great a)------------odd time workouts.Its smooth surface is easy b)-----------the legs.You can add different progamming c)------------ go uphill and adjust the speed. A grass track d)-------------parks is the best surface for running but it is difficult to find long and even patches in the cities

a) (i)by      (ii)in             (iii)for              (iv)to
b) (i)on     (ii)to             (iii)in                (iv)between
c) (i)to       (ii)from        (iii)through     (iv)along
d) (i)over  (ii)below      (iii) in               (iv)through