It was fortunate that the weather last winter was quite mild. (s

It was fortunate that the weather last winter was quite mild. (sentence with –ly opener)
【正确答案】：Fortunately, the weather last winter was quite mild.
【题目解析】：–ly opener的本质就是副词做状语并前置的句法形式。所以，本题中，在不改变原来句子意思的前提下，我们将形容词变为副词，并使其做前置状语既可。