<span>Zagros and Taurus Mountains.</span>
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.
Learn more about Eratosthenes, here:
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Answer:
c. civil service examinations
Explanation:
In order to fill government positions, the Tang, Song, and Ming dynasties all used CIVIL SERVICE EXAMINATIONS.
In ancient China, imperial examinations were used to select government officials using written examinations and this use of meritocracy was influenced during the Tang Dynasty.
The Tan, Ming and Song Dynasties all used examinations to test the knowledge of candidates on subjects like Chinese classics, poetry and administrative issues.
Answer:
a=0
Explanation:
5=5+2a
5-5=2a (Inverse operation of addition)
0=2a
0/2=2a/2
0=a