What made the tang people so smart in what they did? I mean how intelectuall were they?

There should be at least four reasons:
1. The wise leadership of the rulers, such as Emperor Taizong and Empress Wu Zetian.
2. The rulers could make full use of the intellects and talents to help with the administration of the country.
3. There were good policies that charged less tax from the farmers, so people lived a happy and peaceful life. Also due to that, people started to run business or have developments in other aspects to make the whole society prosperous.
4. During that time, there were international trades with other countries to improve the prosperity of the dynasty.

Just for your reference!

Thank You Sooooo much! Im sure ill get an A!