A contour line<span> or isoline </span>connects points<span> on a map that are of </span>equal<span> value. Examples of contour </span>lines<span> or isolines are isobars (pressure) and isotherms (</span>temperature<span>). Perhaps the prototypical example of a contour </span>line<span> is that which </span>connects points of equal<span> elevation (that is, height above sea level).</span>
Answer: 180 degrees longitude
Explanation: I just looked it up
Hydrosphere and atmosphere. those are the only 2 spheres that interact with each other in the air.
