●Extreme Programming(XP)is a discipline of software development with __(71)__ of simplicity，communication，feedback and courage.Successful software development is a team effort–not just the development team，but the larger team consisting of customer，management and developers.XP is a simple process that brings these people together and helps them to succeed together.XP is aimed primarily at object-oriented projects using teams of a dozen or fewer programmers in one location.The principles of XP apply to any __(72)__ project that needs to deliver quality software rapidly and flexibly.
An XP project needs a __(73)__ customer to provide guidance.Customers，programmers，managers，are all working __(74)__to build the system that’s needed.Customers–those who have software that needs to be developed–will learn simple，effective ways to __(75)__ what they need，to be sure that they are getting what they need，and to steer the project to success.
（71）A．importance
B．keys
C．roles
D．values
（72）A．small-sized
B．moderately-sized
C．large-sized
D．huge-sized
（73）A．part-time
B．casual
C．seldom
D．full-tim
（74）A．together
B．by themselves
C．separately
D．alone
（75）A．tell
B．know
C．communicate
D．feedback