fused heterocycle

例句：

1. 1. The study of fused heterocycles is a hot topic in the field of chemistry.
   杂环化合物的研究是化学领域的热门话题。
2. 2. The new drug was designed to treat diseases caused by fused heterocycles.
   这种新药被设计来治疗由杂环化合物引起的疾病。
3. 3.Fused heterocycles have unique properties that make them useful in various applications.
   杂环化合物具有独特的性质，这使得它们在各种应用中非常有用。