Which of the following is a similarity between the Huang River and Indus Valley civilizations?

the use of bronze ritual vessels

a social class system with farmers at the bottom

the exchange of ideas with other cultures

the use of a metal currency 


How were the civilizations of the Huang River valley and the Nile River valley similar?

Both began around 4000 BCE.

Both arose in desert regions.

Both failed to develop a writing system.

Both were ruled by dynasties.