The diagram below shows the development of cutting tools in the Stone Age. Summarize the information by selecting and reporting the main features, and make comparisons where relevant.
The diagram illustrates the advance in the craftmanship of people during the Stone Age in making cutting instruments. Overall, what stands out from the picture is that the latter design appeared to be more refined and sharper compared to the former even though both were similar in length.
Tool A, which dated back 1.4 million years ago, was very primitive and basic. Seen from the front, it has a wider middle part and smaller and blunt ends with a rough edge. The side was smaller, and the back of the tool had a pointier top in comparison with its front.
After 0.6 million years, tool B saw some improvements in size and finishing quality while the length stayed unchanged, at 5cm. From the front, it looked like a water drop with a much more finely sharpened edge. The side was significantly smoother as opposed to the older version, and the back had a more regular shape and more even surface.