What inference can be drawn about how zheng he affected the world’s knowledge about china?

Aging populations can be a problem for developed countries because a) there are fewer younger workers coming into the workforce. b) most older workers demand top-level pay and full benefits. c) many older people are skilled in manufacturing, not technology. d) younger workers cannot find jobs when older people work longer.

Which statement describes a similarity between the great migration and to this day

The map shows information about river valley civilizations. which feature of this map best the reader determine the distance between two places?