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Scolex (head) of the tapeworm Taenia solium. The hooks of the scolex enable the tapeworm to attach to the intestinal wall.
Uninvited Guests: The 7 Worst Parasitic Worms
Black widow spider
9 of the World’s Deadliest Spiders
The impeachment trial of Pres. Andrew Johnson, illustration from Frank Leslie's Illustrated Newspaper, March 28, 1868.
What If the President Is Impeached?
Comparison of a hare and a rabbit. (Left-hare) black-tailed jackrabbit (Lepus californicus); (right-rabbit) desert cottontail (Sylvilagus audubonii)
What’s the Difference Between Rabbits and Hares?
Space race (1957-1969) infographic between United States (U.S.) and Russia. America, Soviet Union, U.S.S.R., space exploration
Timeline of the Space Race, 1957–69
King Cobra snake in Malaysia. (reptile)
9 of the World’s Deadliest Snakes
American bison (Bison bison) also known as buffalo or plains buffalo on the prairie, western U.S.
What’s the Difference Between Bison and Buffalo?

roadbed

railroad track

Learn about this topic in these articles:

railroad construction

  • high-speed train
    In railroad: Location and construction

    …also helped to improve railroad roadbeds in other ways. Where the roadbed is unstable, for example, injecting concrete grout into the subgrade under pressure is a widely used technique. In planning roadbed improvements, as well as in new construction, railroads have drawn on modern soil-engineering techniques.

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