This paper discussed purposes , functions and management of software engineering , enucleated principles it should follow .
本论文探讨了软件工程的目的、作用及管理方法，阐明了软件工程应遵循的原则。
John gurdon 's work dates back to the 1950s and 1960s , when he showed that nuclei from adult cells of the xenopus frog could be transplanted into an enucleated egg and give rise to healthy frogs the first example of animal cloning .
