The way that scientist determine when an era begins and when it ends is : Mass extinction of an organism
For example, millions years ago, the world was under the era of dinosaurs, which were simply the most superior beings on earth during that time, after they became extinct, the earth enter the era of the mammals
Answer:
C-A relationship between variables
Explanation:
People of the different countries and different region who migrated and settled down in America makes the United States as a Multicultural nation.
Explanation:
United States has a long history of Migration where first the Americans (initially slaves) demanded their right to live in America properly without being discriminated on the basis of rights provided by the constitution.
After that the Germans and then Chinese, Irish and other Eastern Europeans migrated to United States. People with different culture and different religion thoughts make United States as a Multicultural nation.
Over the next ten years, the world population will grow. Experts expect that there will be more older people in the population rather than younger one.
Increases in a population's or a dispersed group's membership are referred to as population growth. Around 83 million people, or 1.1% of the world's population, are added every year. From 1 billion people in 1800 to 7.9 billion in 2020, the world's population has increased.
There are currently 703 million individuals who are 65 or older, and by 2050, that figure is expected to increase to 1.5 billion. The UN DESA Population Division's most recent population estimates and predictions indicate that by 2050, 1 in 6 of the world's population, up from 1 in 11 in 2019, will be over 65.
To learn more about population, refer
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