The Great Wall of China was not built in a continuous period.
Why it is true
The wall was built in various phases over more than 2,000 years, by different dynasties.
Source: Historical Research
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This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.