It is the first / second time.that.是什么丛句
问题描述：
It is the first / second time.that.是什么丛句
答
主语从句,it为形式主语,不过已经固定成了句型了.
itis the first time that sb.have done sth.
这是某人第一次做某事
it was the first time that sb.had done sth.
that 从句中要用完成时