—Could you tell me whom the radio _____ by?

—Sorry, I have no idea. [ ]

A. invents

B. invented

C. is invented

D. was invented

环己酮（A）-环己醇（B）混合液（可视为理性溶液）在真空度88.73kPa、温度90℃下达到相平衡状态。求气液两相的组成、相对挥发度及气相中A、B两组分的摩尔数之比。

注：环己酮和环己醇的安托因方程为：

式中p⁰单位为kPa，t单位为℃。