有关影响需求弹性的主要因素的叙述，下列不正确的是( )。A．通货膨胀 B．商品耐用

移动电话的资费结构为（）。

驱动共阳极七段数码管的译码器的输出电平为低电平有效。

急性胰腺炎时，下列不是手术适应证的是（）

A.胰腺坏死合并感染

B.肠道感染

C.胰腺脓肿

D.胰腺假性囊肿

E.胆道梗阻

Which of the following statements about portfolio risk is true（）

A. In the absence of perfectly positive correlation, a portfolio will always have lower risk than the average risk of the component assets.

B. In the absence of perfectly positive correlation, a portfolio will always have lower risk than the risk of each of the component assets. 

C. In the absence of perfectly negative correlation, a portfolio will always have lower risk than the risk of each of the component assets.

奶油胶冻中的馅料，一般包括鲜奶油、牛奶、蛋黄等。（）