Answer:
Among the earliest inventions were the abacus, the sundial, and the Kongming lantern. The Four Great Inventions,the compass, gunpowder, papermaking, and printing – were among the most important technological advances, only known to Europe by the end of the Middle Ages 1000 years later.
Explanation:
Big and heavy army to protect them
Japan invaded Manchuria.
They did this because Manchuria was poorly defended and had many resources.
It had living space for their surplus population and Manchuria had enough raw materials, food and other goods that would make Japan self-sufficient.
