与全口义齿大气压力的产生关系最密切的一项是（）
A.基托面积大小
B.牙槽高低
C.边缘封闭区好坏
D.腭穹隆的高低
参考答案：C
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In your spoken English class, your teacher shows you the following picture. You are asked to describe the picture and explain how you understand it.
下列哪些国际业务发生时需经有权人审批（）。
A.进出口押汇
B.贸易融资
C.打包放款
D.福费廷、出口票据贴现
