All the tickets having been sold out与As all the tickets had been sold out都一个意思为什么用as

题目

All the tickets having been sold out与As all the tickets had been sold out都一个意思为什么用as

答案

尽管意思一样但是结构不同,前者是独立主格结构,而后者是一个完整的句子,是由
as引导的原因状语从句.