Answer:
The Chinese kept the secret o silk production so carefully because The production generated great wealth for china as long as it was not shared.
Step-by-step explanation:
All right to understand this answer we need to analyze the context. The Chinese discovered the production of silk so early in their culture that they even created a legend about it instead of revealing the real way. So, that meant it was incredibly important for them. Also, the Chinese profited incredibly from it and the silk road was created only to trade silk. So, as long as they kept it in secret. no one else would have got profit out of it and they could control the market.