败血症做血培养，何时抽血培养阳性率最高（）
A．发热开始
B．寒战以后
C．发热达高峰时
D．寒战、发热以后
E．寒战、发热之前
参考答案：E
Configuration management system can be used in defining approval levels for authorizing changes and providing a method to validate approved changes.（）is not a project configuration management tool.
A.RationalClearcase
B.QualityFunctionDeployment
C.VisualSourceSafe
D.ConcurrentVersions System
对于滚动轴承的轴系固定方式，请解释什么叫“两端固定支承”？
