Both the shang dynasty and the xia dynasty were located along what river?

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.

Where did people have to work with great organization to be successful at farming? a. on the yellow river basin c. on the hangzhou bay b. on the yangzi river basin d. on the hubei basin

Which of the following does not describe europe after that fall of the western roman empireh