语法填空
China is the birthplace of silk. Raising silkworms for silk production (date) back to over 6,000 years ago. Legend has it that the wife of the Yellow Emperor was having tea under a mulberry tree(桑树) a cocoon(蚕茧)fell into her cup. As she watched, the cocoon spun a strong white thread. She unwound the string onto her finger, (realize) that it could be used as weaving thread. Thus an industry was born. She taught her people how to raise silkworms, and (late) invented the loom(织布机). Silk production reached high level during the Shang Dynasty (1600BC—1046BC).
For more than two thousand years, the Chinese kept the secret of silk to(they). It was one of the most guarded(secret) in history. Anyone found guilty of taking silkworm eggs, cocoons, or mulberry seeds was put to death. Silk clothes were worn by emperors and rich people and became a symbol wealth. Common people were prevented from wearing silk. With the increases of travels and trading, sericulture (slow) reached the outside world from Asia to Europe. Now most of silk (produce) in the south of the Yangtze River Delta, such as Suzhou, Hangzhou, Nanjing, and Shaoxing.
答案:【1】dates【2】when【3】realizing【4】later【5】a【6】themselves【7】secrets【8】of【9】slowly【10】is produced