This is the mountain village ________ I stayed last year. 2.This is the mountain village ________ I visited last year, .3.I'll never forget the days ________ I spent in the countryside. 4.I'll never forget the days ________ I worked together with you. 5.I forget the time ________ he will come. 6.I forget the time ________ he told me. 7.The reason ________ he can't come is that he is ill. 8.The reason ________ he told me is not true. 9.This is the factory ________ I visited last year. 10.This is the factory _______ I worked last year. 11.This is the factory _______ produces all kinds of TV sets. 12.This is the reason ________ he was absent. 13.This is the reason _______ can explain his absence.