To make them, our ancestors sharpened stone or bone tips and whittled sticks into a shaft.

为了制作它们，我们的祖先把石头或骨头尖削尖，把棍子削成一个轴。

For example, one thing they study is hafted weapons, spears made by mounting a sharpened stone or bone onto a stick.

例如，他们研究的一件物品是用斧头武器——把锋利的石头或骨头装在棍子上制成的长矛。

These people left behind small, sharpened stones with pointed ends.

这些人留下了尖锐的小石头。