CT质控测试认为，理想的水模CT值应为（）
A.±3HU
B.-1000HU
C.+1000HU
D.0HU
E.±5HU
参考答案：D
-Is Chinese teacher?
-Yes, is.[ ]
A. she you, she
B. her you, she
C. she your, she
D. her your, he
矿井主要通风机的反风设施有哪些规定和要求？
