silk
Trick question... The wall is the guard.
How did red became lucky in china
china became a country in 1546
As contact with people from other lands increased, the Chinese realized how valuable their silk was as an item of trade. So, the techniques of silk production became a closely guarded state secret. Because of the worldwide demand for silk, Chinese commerce expanded along the Silk Roads to most of Asia and, through India, all the way to Rome.
The wall was guarded by soldiers and guards, but the wall was a guard, too. Even though, because Mongolians might have a surprise attack, so guards and soldiers kept good watch
They have a secret cult in China! They want to eat you
overcrowding in china
Because a wall alone is not enough to keep invaders out unless the wall is guarded.
Silk was kept secret b/c of its value
When Russia became comunist they went to China, and became buddies.
Chiang Kai-shek became the President of China in 1928.