B. Cultural heritage refers to the valuable traditions, customs, artifacts, and knowledge that are passed down from previous generations and preserved.

Here are the answers to your questions:

1. B. Cultural heritage refers to the valuable traditions, customs, artifacts, and knowledge that are passed down from previous generations and preserved.

   • Answer: $\boxed{\text{B}}$

2. C. The United Nations Educational, Scientific and Cultural Organization (UNESCO) adopted the Mexico City Declaration on Cultural Policies in 1982.

   • Answer: $\boxed{\text{C}}$

3. C. Culture is considered highly perishable because if its knowledge, practices, and values are not actively transmitted and passed down to younger generations, they can be lost or disappear over time.

   • Answer: $\boxed{\text{C}}$

4. B. Culture encompasses the entire present way of life of a people, including their beliefs, customs, and practices. Cultural heritage is a specific part of culture that consists of the customs, traditions, knowledge, and practices that have been inherited from past generations and are valued for preservation.

   • Answer: $\boxed{\text{B}}$

5. C. Culture is dynamic and changes over time due to a combination of internal factors (like innovation and social evolution within a society) and external influences (such as colonization, modernization, and globalization), which can significantly alter beliefs and practices.

   • Answer: $\boxed{\text{C}}$