Before paper (1) ____________ (invent), people wrote or drew on materials such as bamboo, silk, animal skin and wooden blocks. Writing materials were really expensive and few people learned to read. Therefore, few people wrote. This all changed, thanks to a man (2) ____________ (name) Cai Lun.
We know that paper had already existed (存在) in China, (3) ____________ the process (过程) of producing it was difficult and the paper was of low quality. Cai Lun began experimenting (试验) with many different materials and different methods (4) ____________ (turn) those materials into paper. In the year 105, he made it from tree bark, bamboo, cloth rags and fishing nets. His paper was stronger and cheaper than any paper that had been made before.
With Cai Lun’s paper-making method, Chinese culture grew more (5) ____________ (quick) over the next several (6) ____________ (century). That’s because ideas were much (7) ____________ (easy) to share and more people learned to read. The use of paper spread abroad, helping other cultures record and spread (8) ____________ (they) ideas. Cai Lun’s paper is considered the (9) ____________ (nation) treasure in China. But (10) ____________ whole world should remember the clever Chinese paper-maker forever.

1. was invented 2. named 3. but 4. to turn 5. quickly
6. centuries 7. easier 8. their 9. national 10. the