Why did early chinese civilizations and dynasties thrive for thousands of years with little outside influence?

a: the great wall prevented invasions

b: the chinese did not need to trade for goods and resources

c: mountains and deserts provided natural barriers

d: china is protected by water on all sides

C: Mountains and deserts provided natural barriers

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radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.