Manhattan语法中的一道题，求解，谢谢？

feifeionly

15. The patient's rare disease was treated using novel techniques developed at the medical school.

Using novel techniques: INCORRECT. This modifier is dangling, since the sentence contains no noun that is properly modified by using novel techniques. To fix the sentence, we can introduce an agent who actually used the novel techniques (e.g., a doctor), or we can switch to a prepositional phrase, such as through the use of novel techniques, that does not contain an -Ing verb form.

Correction: The patient's rare disease was treated through the use of novel techniques developed at the medical school. 这样修改有点小疑问：为何使用介词短语，它在句中作什么成分，是作定语修饰它之前的The patient's rare disease was treated吗？使用介词短语了为何可以保持整个句子之前的样子？