Fill in the blank with an appropriate phrase. models address specifications, requirements, design, verification and validation, and maintenance activities.
Answer(s): A 
Explanation:
A life cycle model helps to provide an insight into the development process and emphasizes on the relationships among the different activities in this process. This model describes a structured approach to the development and adjustment process involved in producing and maintaining systems. The life cycle model addresses specifications, design, requirements, verification and validation, and maintenance activities.