causal chain

例句：

1. 1. The cause of the disease is still unknown.
   这种疾病的原因仍然未知。
2. 2. This study aims to investigate the causal chain of the relationship between education and economic growth.
   这项研究旨在调查教育与经济增长之间的关系因果链。
3. 3. The researcher found a causal chain that linked environmental pollution with climate change.
   研究者发现了一个将环境污染与气候变化联系起来的因果链。