热壁加氢反应器不宜采用下列哪些壳体结构（）
A.单层卷焊；
B.热套；
C.锻焊
D.多层包扎；
参考答案：B, D
_____ is known to us all is that the Chinese government has spared no efforts to protect people from fake food. [ ]
A. As
B. It
C. That
D. What
耳鼻咽喉科感染后引起败血症、球结膜水肿、眼球突出，提示（）
A.横窦血栓形成
B.额骨骨髓炎
C.海绵窦血栓形成
D.脑脓肿
E.Bezold脓肿
