that在这个句子中是什么用法?
问题描述：
that在这个句子中是什么用法?
But so many were planted that the protective forest managed to maintain its size,despite the great storms and the cruel felling of the evil beings.
答
so...that 如此...以至于
so是副词
that引导结果状语从句
种的树足够多以致森林的面积能够得到保持