How long did it take for Li Bing to create his irrigation channel?​

about seven years

Explanation:

The cracked rock was cleared away and the process started all over. It took about seven years to cut a channel through the rock.

Over 2,200 years ago, the city was threatened by the frequent floods caused by flooding of the Minjiang River (a tributary of the Yangtze River ). Li Bing, a local official of Sichuan Province at that time, together with his son, decided to construct an irrigation …

Explanation:

by 1890, the united states had by far the world's most productive economy. american industry produced twice as much as its closest competitor--britain. but the united states was not a great military or diplomatic power. its army numbered less than 30,000 troops, and its navy had only about 10,000 seamen. britain's army was five times the size of its american counterpart, and its navy was ten times bigger. the united states' military was small because the country was situated between two large oceans and was surrounded by weak or friendly nations. it faced no serious military threats and had little interest in asserting military power overseas.

franklin d. roosevelt

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