To avoid the damage of nose of crossing, the wing rails are ramped so that nose of crossing remains at a lower level by

To avoid the damage of nose of crossing, the wing rails are ramped so

1.	To avoid the damage of nose of crossing, the wing rails are ramped so that nose of crossing remains at a lower level by
A.	3 mm
B.	4 mm
C.	5 mm
D.	6 mm.
Answer» B. 4 mm