当发生回火时，应立即关闭切割氧调节阀，然后关闭（）及预热氧调节阀。
参考答案：乙炔调节阀
属于肺血栓栓塞症原发因素的是（）
A.抗凝血酶缺乏
B.脊髓损伤
C.腹部大手术
D.肾病综合征
E.急性心肌梗死
_____ your advice, I'm sure to consider it and give you reply in time. [ ]
A. In spite of
B. But for
C. Because of
D. As for
