男,21岁,腰部不适,晨起加重半年余,X线检查如图,最可能的诊断是()
A.类风湿关节炎
B.脊椎退行性变
C.强直性脊柱炎
D.化脓性脊柱炎
E.阻滞椎
参考答案:C
I _______ English since I was very young but still can't communicate fluently in it. [ ]
A. study
B. have been studying
C. studied
D. am studying
氧枪喷头损坏的原因和停用标准是什么?