Since customs are the products of history, they inevitably change with the development of history. Everything that can exist has its dependent natural conditions and social environment, changes in the vicissitudes of the sea, economic development, and institutional changes. Changes, the decline of some old customs is just like the rise of new customs. It is the metabolism of nature and society. It is a reasonable phenomenon. The decline does not necessarily have to be revived, and some may wish to allow themselves to die. The script has disappeared, and the Institute of Minority Languages of the Chinese Academy of Social Sciences once helped these ethnic groups to restore the script, but it was contrary to their wishes and was not welcomed by the locals, because they thought that learning the script of their ethnic group could not leave their hometown and would rather learn Chinese characters. Since this kind of text has existed in history, it is a cultural heritage worth cherishing. It needs to be preserved in historical memory as a cultural relic, so that modern people can perceive the wisdom of their ancestors and make them "dead without forgetting. ". What does this passage mean? ['Customs should be treated from the perspective of historical development.', 'Customs is an intangible heritage that cannot be copied.', 'Changes in customs are the result of a combination of factors.', 'Customs should be vigorously protected as a cultural heritage.']