Valley curves are required to be introduced at the situations where -
(a) a negative grade meets a positive grade
(b) a negative grade meets another milder negative grade
(c) a negative grade meets a steeper positive grade
(d) all of the above.
The correct Answer Is
(d) all of the above
(a) a negative grade meets a positive grade
(b) a negative grade meets another milder negative grade
(c) a negative grade meets a steeper positive grade
(d) all of the above.
The correct Answer Is
(d) all of the above