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3 天前 · This is a list of countries and other inhabited territories of the world by total population, based on estimates published by the United Nations in the 2022 revision of World Population Prospects. It presents population estimates from 1950 to the present. [2] List. Data are mid-year [3] estimates from the United Nations and are for 2022 and 2023.
5 天前 · The United Nations Educational, Scientific and Cultural Organization ( UNESCO) [a] is a specialized agency of the United Nations (UN) with the aim of promoting world peace and security through international cooperation in education, arts, sciences and culture. [2] [3] It has 194 member states and 12 associate members, [4] as well as partners in ...
1 天前 · In a DNA double helix, each type of nucleobase on one strand bonds with just one type of nucleobase on the other strand. This is called complementary base pairing.Purines form hydrogen bonds to pyrimidines, with adenine bonding only to thymine in two hydrogen bonds, and cytosine bonding only to guanine in three hydrogen bonds. . This arrangement of two nucleotides binding together across the ...
1 天前 · Science is a rigorous, systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the world. Modern science is typically divided into three major branches: the natural sciences (e.g., physics, chemistry, and biology), which study the physical world; the social sciences (e.g., economics, psychology, and sociology), which study individuals ...
1 天前 · However, since 2015, investment in non-hydro renewable energy has been higher in developing countries than in developed countries, and comprised 54% of global renewable energy investment in 2019. The International Energy Agency forecasts that renewable energy will provide the majority of energy supply growth through 2030 in Africa and Central and South America, and 42% of supply growth in China.
2024年6月3日 · Demographics of Earth. Population pyramid of the world in 2022 by the UN. Population. Over 8,000,000,000 (estimated) Fertility rate. 2.27 (2021) Earth has a human population of over 8 billion as of 2024, with an overall population density of 50 people per km 2 (130 per sq. mile). Nearly 60% of the world's population lives in Asia, with almost 2 ...
19 小時前 · The United Nations in 1945, after World War II.In light blue, the founding members. In dark blue, protectorates and territories of the founding members. The UN officially came into existence on 24 October 1945, after ratification of the United Nations Charter by the five permanent members of the United Nations Security Council (the Republic of China, France, the Soviet Union, the United ...
