Trains have developed over the years as technology has improved. Now, there are electronic trains that do not need conductors to run them. These conductorless electronic trains are beneficial because , but they also have disadvantages such as .

sorry, is there a picture? i do not see any arrows.

wut? unius0123 wut?

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.