complexes

例句：

1. 1. The chemistry of these compounds is quite complex.
   这些化合物的化学性质相当复杂。
2. 2.The scientists have identified several new compounds that could be used in medicine.
   科学家们已经识别出几种新的化合物，它们可能在医学上有所应用。
3. 3. The study of complex systems is a field of active research.
   研究复杂系统是一个活跃的研究领域。