4 presidents were killed, Abraham Lincoln, James A. Garfield, William McKinley, and John F. Kennedy.
Hi
The answer is : 1
Collective learning.
The equal-field system (Chinese: 均田制度; pinyin: Jūntián Zhìdù) or land-equalization system was a historical system of land ownership and distribution in China used from the Six Dynasties to mid-Tang dynasty. ... The system was eventually adopted by other kingdoms and its use continued through the Sui and Tang dynasties.
