我国上海市龙阳路至浦东机场的磁悬浮列车最高速度达431km/h。磁悬浮列车是利用          （填“同名”或“异名”）磁极的相互排斥来实现列车悬浮的。悬浮的目的是                              。

We have been told that under no circumstances we can use the telephone in the office for personal affairs.

A．did we use

B．may we use

C．we may use

D．we could use