What was done to protect the Chinese empire against Invaders? O they attacked the enemies first
O built the Great Wall
Omore soldiers were drafted
O installed fortifications on the rivers

They built the Great Wall

Explanation:

The Ming dynasty built a giant wall stretching 5,000 miles to keep invaders out of China, but how effective was it against the enemy? The Great Wall is nearly 30 feet high along some stretches, and often built through rugged and mountainous terrain, such as the Huanghuacheng region near Beijing.

the two things that develop a strong social foundation are: a. separation of church and states e. education received attention separation of church and states separate the illogical  argument that came from religious beliefs to a fact based belief. while education will make us remember the past to avoid the repeat of our mistakes.

besides the fact that abraham lincoln abolished slavery, and greatly benefit black people, he had a heavy impact of the definition of what democracy was, and should be.