September13,1931 is the day__ we’ll never forget.a.when b.on

I’ll never forget the days----I spent on the farm. A.when B. I'll never forget the days we lived together.A that B when 为 I’ll never forget the time when (=on which) we worked on the that is the day ( ) I'll never forget.A.which B.on which c.i I `ll never forget the day ___ I joined the club.a.when b.wh 5.That is the day ______I'll never forget.\x0bA.which B.on w September 18,1931 is the day that we'll never forget.为什么用tha September 15,2000 is the day__we'll never forget. A.that B.w I'll never forget the day when we met for the first time. I'll never forget the day on which\when I joined the party.解 That is the day_____I'll never forget when后面为什么加过去式,如I"ll never forget the days shen we studied to