What was the first medium of exchange in china

Cowry shells are believed to have been the earliest form of currency used in Central China, and were used during the Neolithic period. Around 210 BC, the first emperor of China Qin Shi Huang (260–210 BC) abolished all other forms of local currency and introduced a uniform copper coin.

the dust bowl, otherwise known as the dirty thirties, was a huge dust storm that killed multiple (and i mean  multiple) farmer's crops, leaving them homeless, and foodless, and jobless. in california, there were 5.7 million residents, and the population shrank as mexicans were repatriated. however, when the dustbowl happened, a lot of people began to move to california. by 1940, 250,000 people had arrived. therefore, your answer would be  the population increased, massively.  i hope this !

explanation:

d. dr. francis collins