Currency Trading Exchange Guide

what is the difference between autocracy, oligarchy, and democracy?
i have a study guide, and can’t figure out that question
or:
how are farmers in Japan been able to raise crops in a land that is very mountainous?
or
Why does international trade involve an exchange rate of currency?
or
how to describe China’s economy today.
The answer above is way off-base.
Autocracy is a government where all the power rests in one person
An Oligarchy is a government where the power is held by a few select individuals
Democracy is a government where, in theory for sure, the power is held by the people, the masses.
As for Japan, maybe terraces?
As for Int’l Trade, an exchange rate of currency is required for, basically, accounting purposes. For example, when China sells a product to the US, China’s costs to produce the product are in Chinese money (Yuan), and to determine their profits, losses, needs, etc., they need to make sure what they get in US dollars is what they need or want in Yuan. Each nation’s currency has a value that changes 24/7 for several reasons. One day, the US dollar might be worth 100 Yuan, the next, 95 Yuan. You want to sell your product or write contracts to reflect the difference is value/costs to China and US, etc., to make sure you get the deal you want based on the value of your product, etc. and the value of currency used to purchase or produce the product.
As for China, China is a hybrid between communist (command) and capitalist (free market) economies, leaning heavily capitalist.
Currency Trading Guide : How Safe Is Currency Trading?