— We’ll have _______ holiday in June. Will you go home?

— No. If I go home, I’ll have to take_______ ride.

A．a one-week; seven days

B．an one-week; a seven day’s

C．a one-week; a seven days’

D．an one-week’s; a seven days’

选相元件是保证单相重合闸得以正常运用的重要环节，在无电源或小电源侧，最适合选择（）作为选相元件。

A、相电流差突变量选相元件

B、零序负序电流方向比较选相元件

C、低电压选相元件