铣床水平调整要求是，纵向和横向的水平在1000mm长度上均不超过（）mm。
A.0.005
B.0.01
C.0.04
D.0.10
参考答案：C
— Can you go shopping with us?
— Sorry, I can't. I _____ my house. [ ]
A. cleaning
B. am cleaning
C. clean
D. cleaned
维生素D缺乏性佝偻病早期诊断实验室检查的灵敏指标是
A．25-(O2D3降低
B．血磷降低
C．甲状旁腺素增高
D．碱性磷酸酶增高
E．血钙降低
