Give an example of how to understand the essence and eliminate the dross

For example, the process of extracting gold from gold-bearing ore by crushing the ore and then melting it at high temperatures is "taking the best and removing the dross."

Another example: the 1979 "reform and opening up", we learn from the capitalist countries of the economic mode of operation, to activate the economy and rationalize the allocation of resources to enhance the economic vitality of our country, but we do not learn from all of the capitalist countries, such as different political cultures and social customs and other dregs, we selectively accept and accept the dregs of the capitalist countries. However, we do not absorb all the things of capitalist countries, such as the dregs of different political cultures and bad social customs. This process is also "take the best, eliminate the dross."