it gives you a certain direction, north, south,east,west, and in-between!
This is known as the visible spectrum of electromagnetic radiation, or visible light. This is the frequency of light that we see, and which illuminates our world as it reflects off of objects. Compared to the full spectrum of electromagnetic radiation, the visible light portion is actually quite small.
A. Convicts
The reason why convicts is the correct answer is because people were at first sent to Australia with the sole reason of serving their sentence there. For that reason, a great proportion of people at the time were simply convicts.
The resulting erosion at the base of a waterfall can be very dramatic, and cause the waterfall to "recede." The area behind the waterfall is worn away, creating a hollow, cave-like structure called a "rock shelter." Eventually, the rocky ledge (called the outcropping) may tumble down, sending boulders into the stream
