it is April 29 ,2011(when)Prince William and Kate Middleton
it is April 29 ,2011(when)Prince William and Kate Middleton walked into the palace hall of wedding
答案上说这句话是定语从句,而我们老师上课说it was seven o'clock when we reached the station是时间状语从句,the bus left at 7 o'clock,when we reached the station 是定语从句.
我们老师说错了吗?该怎么区分?