Determine the shape of land forms from the given contour lines. Check whether the places A, B, C and D have intervisibility.
| Places |
Iniervisible/ Not intervisible |
| Between A and B |
............ |
| Between B and C |
........... |
| Between C and D |
............ |
| Between A and C |
............. |
| Between B and D |
.............. |
