The words "1" and "great changes in a hundred years" are usually used to describe the unique and important turning point facing the current era. It shows that this is a rare and noteworthy moment of change on the time scale of one hundred years.

2. Global challenges: We are facing a series of global challenges, such as global public health crisis, climate change, economic instability and geopolitical issues. The complexity of these challenges and their interrelationships make the current period different from the past centuries.

3. Rapid development of science and technology: Scientific innovation and scientific progress are changing our way of life, economy and social structure at an unprecedented speed. Breakthroughs in artificial intelligence, big data analysis, Internet of Things and biotechnology are redefining our times.

4. Economic globalization and social change: Globalization has brought closer ties between countries and regions, and trade, personnel flow and cultural exchanges are accelerating. At the same time, social structure, values and power relations are also undergoing profound changes.

5. Remolding of politics and power: The global political landscape is undergoing a major transformation. The rise of emerging countries, the reconstruction of international cooperation mechanism and the adjustment of global governance system are all changing the pattern of global politics.

6. Social change and cultural change: profound changes have taken place in the culture and values of the current society. Including gender equality, diversity, social justice and other issues, people pay more attention to power and privacy, and the popularity of social media has also had a great impact on information dissemination and social interaction.

7. Environmental crisis and sustainable development: Climate change is one of the most urgent challenges at present, which has a wide impact on the global ecosystem, economy and society. The rise of the concept of sustainable development and the increasingly high voice of responsibility for protecting resources and the environment all put forward higher requirements for our behavior.

8. Social inequality and welfare security: At present, the problem of inequality facing the world is becoming more and more prominent. With the change of economy and society, problems such as uneven income distribution, poverty, social welfare and public services have become one of the focuses of global attention.

9. Digitalization and artificial intelligence revolution: The rapid development of digitalization and artificial intelligence technology is changing our lifestyle, working style and economic model. The rise of automation and machine learning has had a profound impact on the labor market, forcing us to rethink issues such as education, career development and social security.