Which of the following methods of contouring is most suitable for hilly terrain?

Location of contour gradient for a highway is best set out from ............

Theory of probability is applied to ............

The construction of optical square is bases, on the principle of optical ............

Benchmark is established by ............

The most reliable method of plotting a theodolite traverse is ............

The difference between the most probable value and its observed value is ............

The chord of a curve less than peg interval, is known as ............

In chain surveying, perpendiculars to the chain line, are set out by ............