下列哪种学说不属于局麻药产生神经阻滞的原理（）
A.受体部位学说
B.闸门控制学说
C.表面电荷学说
D.膜膨胀学说
E.钙离子学说
参考答案：E
—Which one would you like to work for in the following groups, Li Mei?
—Let me see. I'd like to work for _____ because this group helps children in poor countries. [ ]
A. Greenpeace
B. NBA
C. UNICEF
D. WTO
本月销售不动产应纳营业税( )万元。
A．75
B．80
C．85
D．90
