寿命不等的互斥方案的经济效果的比选，关键在于(    )。
   A．独立方案组合    B．增量投资收益
   C．借款偿还能力    D．使比选的基础相一致

根据材料回答12~15题：How does the woman feel at the beginning of the conversation?[A]Angry. [B]Surprised. [C]Sad. 点击查看答案

What size bag does the woman want?[A]A 24-inch bag. [B]A 29-inch bag. [C]A 32-inch bag. 点击查看答案