Trenches were dug in a zigzag pattern so that if an enemy entered the trench, he could not fire straight down the line. ... The main trench lines were connected by communicating trenches, allowing for the movement of messages, supplies, and soldiers and were lined with barbed wire.
The important contribution to navigation made by Eratosthenes in the third-century bc was a reasonably accurate calculation of the circumference of our planet.
Who is Eratosthenes?
Eratosthenes was born in 276 BC and died in 194 BC. He was a well-known poet, mathematician, a researcher in geography, and theorist of music. He was the first to gauge the size of the planet.
The Earth was first measured by Eratosthenes of Cyrene. The precise measurement of Earth's circumference was greatly aided by Eratosthenes' work in the third-century bc.
As a result, the Eratosthenes in the third century bc accurate calculation of the Earth.
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Answer:On September 3, 1939, in response to Hitler's invasion of Poland, Britain and France, both allies of the overrun nation declare war on Germany.
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