单项选择题 The Unified Modeling Language is a standard graphical language for modeling object-oriented software（）can show the behavior of systems in terms of how objects interact with each other.

单项选择题 （）is a property of object-oriented software by which an abstract operation may be performed in different ways in different classes.

单项选择题 The strategies for handling risk comprise of two main types: negative risks, and positive risks. The goal ofthe plan is to minimize threats and maximize opportunities. When dealing with negative risks, there are three main response strategies（）,rransfer ,Mitigate.