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5 天前 · The heart is a muscular organ found in most animals.This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest ...
2 天前 · The tomato ( / təmeɪtoʊ / or / təmɑːtoʊ /) is the edible berry of the plant Solanum lycopersicum, [1] [2] commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. [2] [3] The Nahuatl word tomatl gave rise to the Spanish word tomate, from which the English word tomato derives.
5 天前 · The number π (/ p aɪ /; spelled out as "pi") is a mathematical constant that is the ratio of a circle's circumference to its diameter, approximately equal to 3.14159.The number π appears in many formulae across mathematics and physics.It is an irrational number, meaning that it cannot be expressed exactly as a ratio of two integers, although fractions such as are commonly used to ...
2 天前 · The United Nations Educational, Scientific and Cultural Organization (UNESCO) 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. It has 194 member states and 12 associate members, as well as partners in the non-governmental, intergovernmental and private sector.
3 天前 · Classic explanations include yellow fever, bubonic plague, influenza, smallpox, chickenpox, typhus, and syndemic infection of hepatitis B and hepatitis D. 1,143,000–3,429,000 (estimated 30–90% of population) [68] [69] 1629–1631 Italian plague (part of the second plague pandemic ) 1629–1631. Italy. Bubonic plague.
5 天前 · Mark Elliot Zuckerberg (/ˈzʌkərbɜːrɡ/; born May 14, 1984) is an American businessman. He co-founded the social media service Facebook, along with his Harvard roommates in 2004, and its parent company Meta Platforms (formerly Facebook, Inc.), of which he is chairman, chief executive officer and controlling shareholder. Zuckerberg briefly ...
4 天前 · Infobox references. Sulfuric acid ( American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling ), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is miscible with water.
