凡取丝必用圆正独蚕茧,则绪不乱。若双茧并四五蚕共为茧,择去取绵用。或以为丝则粗甚。 eylQTCuYhdk7kie3fIP9udN21eS24IxGdjf7WXAdliHoKKv41aA7AkVNdklFJBuT