Although schistosomiasis is not often fatal, it is so debilitating that it has become an economic drain on many developing countries. (A) it is so debilitating that it has become an economic (B) it is of such debilitation, it has become an economical (C) so debilitating is it as to become an economic (D) such is its debilitation, it becomes an economical (E) there is so much debilitation that it has become an economical 答案是A。但是C错在哪了呢,他是不是一个倒装啊?so as to逻辑主语也一致了啊、og上说The construction so x as to y is not a correct idiom.什么意思呢 大家指点一下我吧 谢谢