User: What are the four great inventions of Ancient China?
Assistant: The four great inventions of ancient China are paper-making, printing, gunpowder and compass. Paper that was most similar to modern materials, was first invented by a court official named Cai Lun in the early 2nd century China. It was relatively cheap, light and suitable for brush writing, and was produced using bark, rags, wheat stalks and other materials. As for printing, the first book with a verifiable date of printing was a Buddhist sutra that was printed in the Tang Dynasty, around the year of 868. The use of gunpowder technique was first discovered by Chinese monks in the 9th century CE, during their quest for a life-extending elixir. Last but not least, one of the first books to describe the magnetic compass was written by Shen Kuo in the Song Dynasty, 11th Century CE.