Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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James Watt greatly improved steam-engine efficiency.
His work supported the Industrial Revolution.
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Johannes Gutenberg developed a movable-type printing system in Europe.
It greatly expanded the production of books.
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Alexander Graham Bell is commonly credited with the practical telephone.
He received a major U.S. telephone patent in 1876.
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Tim Berners-Lee created the World Wide Web at CERN.
He developed core technologies including HTML and HTTP.
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Edward Jenner demonstrated vaccination against smallpox in the 1790s.
His work helped establish immunization.
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Alexander Fleming discovered penicillin's antibacterial effect in 1928.
The discovery led to the development of antibiotics.
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Dmitri Mendeleev arranged elements in a periodic system.
He also predicted properties of undiscovered elements.
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Albert Einstein developed special and general relativity.
These theories transformed modern physics.
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Isaac Newton formulated three laws of motion and the law of universal gravitation.
His work shaped classical physics.
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Earth's tilted axis changes the angle and duration of sunlight during its orbit.
This produces the seasons.
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Earth rotates on its axis approximately once every 24 hours.
The side facing the Sun experiences day.
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The Moon is Earth's only natural satellite.
It orbits Earth and influences ocean tides.
