妈妈不让西蒙出去，除非他答应今晚十点前回来。

Mum won't let Simon go out unless he promises to be back before 10 o'clock tonight.

youdao

妈妈不让西蒙出去，除非他答应今晚十点前回来。

Mum won't let Simon go out unless he promises to be back before 10 o'clock tonight.

youdao