Q1: Two contour lines, having the same elevation

ANS:D - can unite together.

The First Characteristic of Contours is;

All the points lying on one contour line have the same elevation.

Therefore the contour line have the same elevation can unite together.

Different elevations of contours Do not unit and cross Together except in some cases. But in this question, There are no such cases. And also No Different elevations are there.

So, the Contour line has the same elevation they must unite together. They may cross each other. Contour lines depend upon elevation. Different elevation contour lines never intersect each other but with the same elevation, they unite i.e. they intersect each other. Generally, two contours lines can't cross each other and also can't unit together. But there are two cases in which contours line cross each other i.e overhanging cliff and unit to gather i.e vertical cliff. Two contours of different elevations do not unite together except in the case of the vertical cliff but if there is the same height two contours can unite together.

But there is no chance to the same elevation of contour lines cross each other while drawing a contour line because all the points lying on one contour have the same elevation. Therefore the answer is They can unite together. Ans-D.