【单选题】You have invited a business colleague to lunch. Who pays for the meal?
A.
You because you invited your colleague to lunch.
B.
Your business colleague because she accepted the invitation.
C.
Whichever one of you the waiter places the bill in front of pays.
【简答题】人类的话音信号波形的频率范围一般是 ( )。
【简答题】汉译英 点击____________ 监听数据条目选择的________ 监听所选选项变化的________
【简答题】长方体 的各顶点都在球 的球面上,其中 . 两点的球面距离记为 , 两点的球面距离记为 ,则 的值为 .