But he conceded that the research does not establish a causal link and that the study did not control for many possible variables.
但是他也承认这项研究并未建立一个因果关系的关联，而且该研究没有控制许多可能的变量。
2
Going forward, researchers would like to study the long-term effects of BPA and triclosan in people to see if they can establish a causal relationship.
继续深入的话，研究人员可能会研究BPA和三氯生暴露对人体的长期影响，试图验证二者之间有无因果关系。
3
‘We have identified the causal medical condition underlying Henry’s reproductive problems and psychological deterioration, ’ the authors said in a study published in The Historical Journal.