四通阀的材质是什么()
A、铬锰
B、铬钼
C、钼钴
D、以上均错误
参考答案:B
(71) means that every project has a definite beginning and a definite end.
A.Project phase
B.Unique
C.Closure
D.Temporary
诊断听神经瘤的最佳影像学方法是()
A.X线平片
B.超声检查
C.桥小脑池空气造影
D.CT
E.MRI