the Tv play is about a ture story that happend in Mianyang in 1998 这里为什么用that
问题描述：
the Tv play is about a ture story that happend in Mianyang in 1998 这里为什么用that
答
the Tv play is about a ture story that happend in Mianyang in 1998
这是一句定语从句
先行词story在从句中作主语,所以关系代词用that