停泵水击,主要是因为水泵出口()突然关闭所引起的。
A、闸阀
B、蝶阀
C、安全阀
D、止回阀
参考答案:D
Extreme Programming (XP) is a discipline of software development with (14) of simplicity, communication, feedback and courage. Successful software development is a teameffort - 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 andhelps them to succeed together. XP is aimed primarily at object-oriented projects using teamsof a dozen or fewer programmers in one location. The principles of XP apply to any (15) project that needs to deliver quality software rapidly and flexibly.
An XP project needs a(an) (16) customer to provide guidance. Customers, programmers, managers, are all working (17) to build the system that’sneedeD. Customers - those who have software that needs to be developed - will learn simple,effective ways to (18) what they need, to be sure that they are getting what they need,and to steer the project to success.
(14)应选入()。
A.importance
B.keys
C.roles
D.values
所谓冷挤压压力;是指坯料在冷挤压变形时作用在模具上的()。
A.最大压力
B.最小压力
C.最大、最小压力之差
D.最大、最小压力之和