Spring in Nanjing is very short .It is warm and sunny .People (人们) like to go to the parks on sunny days . It is very hot in summer in Nanjing .People do not like to play balls in the afternoon .They like to go swimming in summer . In autumn , it is cool and sunny. Many people like to come to Nanjing in autumn .In winter , it is cold in Nanjing .Boys and girls like to make snowmen and go skating . They have great fun in winter .

血清白蛋白可用于治疗组织水肿、抗血小板凝集等疾病，科学家利用基因工程技术成功培育出了转基因羊，从其分泌的乳汁中可提取血清白蛋白．请回答下列问题：