The given illustrations depict the progress of tools used for cutting in the Stone Age. Overall, it is obvious that Tool B overcame dramatic modifications to become larger and more sophisticated than Tool A. Regarding tool A, it first appeared about 1,4 million years ago and was used by prehistoric people for various purposes. Tool A was small and did not have a particular shape, just approximately 7-8 centimetres in length. As we can see in the diagrams, this tool was made in a crude way with the front view and back view not identical. Moreover, its edge was extremely blunt which proved that it was not sharpened well. In contrast, tool B showed us that it underwent about 0,7 million years to become more advanced and sharper than tool A. The front view and back view of tool B were almost symmetrical with a water drop shape. Additionally, tool B was not only bigger than tool A but also more pointy and even than tool A which claimed that tool B could be used for many cutting tasks more effectively.