this lesson is that we will never forget.可以这样写嘛?

this lesson is that we will never forget.可以这样写嘛? That is a special day() we will never forget. This is the day____ I will never forget September 18 ,1931 is the day____ we will never forget 1 It is ____that we will never forget That is the day _____I will never forget. 定语从句的疑问.Sep 18 1937 is the day we will never forget.为什么用that we will never forget the days__ we spent together.A that B w people will never forget this history _____ It's ____that we will never forget. I will never forget that terrible accident I will never forget that special day.