ANSWERS
3. Archaeologists found stones bearing carvings of humans that predate the crossing of the strait... This would men that those who made the carvings on the stone were not descendants of those who crossed the Bering Strait, since the crossing of the Bering Strait occurred after the carvings were made
4. Archaeologists found remains of human-made objects such as weapons that predate the crossing of the strait... Just as the first one, this implies that those who made the objects did not descend from those who crossed the Bering Strait.