D, all people involved in a case
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.
Answer:
the return trip was upstream => against the flow of the river.
Long distance communication depended on the memory of a man, long-term memory was needed to teach children, and construction was more slow paced.
