**Question 1:**
Early Chinese rulers established **a centralized state** by conquering and uniting kingdoms under the rule of one emperor. From 624 to the early 1100s, the **Tang Dynasty** ruled over a golden age of prosperity before the Mongols invaded.
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**Question 2:**
The impact that the opium trade had on China was: **It resulted in addiction and conflict.**
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**Question 3:**
After 1945, a civil war in China led to the rise of a(n) **communist** government there.
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**Question 4:**
- **Command economy**: North Korea
- **Market-based economy**: Japan, South Korea
- **Command economy with limited market reforms**: China
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**Question 5:**
In which nation did a nationalist military regime lead the country to invade its neighbors and help launch World War II?
The answer is: **Japan.**