$1.$ List and describe the main tasks that are performed during systems implementation.

$1.3.$ What are the most significant differences among structured, object$-$oriented, and agile methods? What do they have in common?

$6.$ Describe three main types of testing and the order in which they are performed.

$9.$ List and describe the four main system changeover methods. Which one generally is the least expensive? Which is the safest? Explain your answers.