Nationalgeographic 备择方案 & 竞争对手
Explore National Geographic. A world leader in geography, cartography and exploration.
替代品和竞争对手 nationalgeographic.com 在内容、流量和结构方面
Live Science features groundbreaking developments in science, space, technology, health, the environment, our culture and history.
History, Travel, Arts, Science, People, Places Smithsonian Magazine.
The National Geographic Society is a global non-profit organization committed to exploring, illuminating, and protecting the wonder of our world.
Explore the fact-checked online encyclopedia from Encyclopaedia Britannica with hundreds of thousands of objective articles, biographies, videos, and images from experts.
Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our understanding of the world and shape our lives.
Breaking science news and articles on global warming, extrasolar planets, stem cells, bird flu, autism, nanotechnology, dinosaurs, evolution -- the latest discoveries in astronomy, anthropology, biology, chemistry, climate & environment, computers, engineering, health & medicine, math, physics, psychology, technology, and more -- from the world's leading universities and research organizations.
Welcome to A+E Networks EMEA is global broadcaster who reach audiences in over 100 countries, including the UK, Nordics, Benelux, Central & Eastern Europe, Spain, Italy and Germany, Africa, and the Middle East.
We provide science about the natural hazards that threaten lives and livelihoods; the water, energy, minerals, and other natural resources we rely on; the health of our ecosystems and environment; and the impacts of climate and land-use change. Our scientists develop new methods and tools to supply timely, relevant, and useful information about the Earth and its processes.
Whether you have questions about the universe or a molecule compound or what biome you live in, Sciencing.com is your go-to source for all things science.
Explore Lisbdnet.com for vetted academic articles, tutorials, and guides. Your trusted source for unbiased, high-quality educational content.
Dictionary.com is the world’s leading online source for English definitions, synonyms, word origins and etymologies, audio pronunciations, example sentences, slang phrases, idioms, word games, legal and medical terms, Word of the Day and more. For over 20 years, Dictionary.com has been helping millions of people improve their use of the English language with its free digital services.
Take online courses on Study.com that are fun and engaging. Pass exams to earn real college credit. Research schools and degrees to further your education.
JSTOR is a digital library of academic journals, books, and primary sources.
The dictionary by Merriam-Webster is America's most trusted online dictionary for English word definitions, meanings, and pronunciation. #wordsmatter
First published in 1869, Nature is the world’s leading multidisciplinary science journal. Nature publishes the finest peer-reviewed research that drives ground-breaking discovery, and is read by thought-leaders and decision-makers around the world.
Edité par des journalistes expérimentés, The Conversation offre des analyses informées et nourrit le débat sur les grands sujets qui touchent la planète. Mais nous suivons également à la loupe les dernières découvertes et les derniers travaux du secteur académique et de la recherche.
Science news and science articles from New Scientist
Read exclusive biographies, watch videos & discover fascinating stories about your favorite icons, musicians, authors & historical figures.
The Library of Congress is the nation's oldest federal cultural institution, and it serves as the research arm of Congress. It is also the largest library in the world, with more than 162 million items. The collections include books, sound recordings, motion pictures, photographs, maps, and manuscripts.
Take a photo of your homework question and get answers, math solvers, explanations, and videos. Works for Math, Science, History, English, and more.
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Weather Underground provides local & long-range weather forecasts, weather reports, maps & tropical weather conditions for locations worldwide
Lumen Learning offers affordable digital courseware & professional development resources to enhance effective teaching and increase student success. Explore our 50+ college courses today!
The world’s largest and most trusted free online thesaurus. For over 20 years, Thesaurus.com has been helping millions of people improve their mastery of the English language and find the precise word with over 3 million synonyms and antonyms.
Free Online Calculator for finance, math, algebra, trigonometry, fractions, physics, statistics, technology, time and more. Use an online calculator for free, search or suggest a new calculator that we can build. Conversions and calculators to use online for free.
LibreTexts is developing the next generation of open-access texts. Open. Free. Accessible to all.
Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.
Omni Calculator solves 2893 problems anywhere from finance and business to health. It’s so fast and easy you won’t want to do the math again!
The World's most comprehensive free online dictionary, thesaurus, and encyclopedia with synonyms, definitions, idioms, abbreviations, and medical, financial, legal specialized dictionaries
We unlock the potential of millions of people. Our qualifications, assessments, academic publications and original research spread knowledge and spark enquiry.
Springer - Our business is publishing. Throughout the world, we provide scientific and professional communities with superior specialist information;
Search and explore the millions of quality, peer-reviewed journal articles published under the Taylor & Francis and Routledge imprints.
SAGE is a global academic publisher of books, journals, and a growing suite of library products and services.
Pioneers in Language Reference for 200 years. Popular and trusted online dictionary with over 1 million words. Find definitions, meanings, synonyms, pronunciations, translations, origin and examples.