In China at around 200 BC, they discovered that by adding minerals to the clay they could improve both the appearance and the strength of the ceramics.
在公元前200年左右的中国，他们发现通过在粘土中添加矿物质可以改善陶瓷的外观和强度。
2
The earliest libraries existed thousands of years ago in China and Egypt, where collections of records on tablets of baked clay were kept in temples and royal palaces.
中国和埃及早在几千年前就有了最早的图书馆，在这两个国家，烧制陶片上的记录被保存在寺庙和皇宫里。
3
In fact, it became so valuable that it was known as white gold and spies were sent to China to discover what they did to the clay to produce such high-quality merchandise.