Rawlins stresses that it is impossible to prove a causal link between the drug and the deaths.罗林斯强调不可能证明该药物与这几起死亡事件存在因果联系。

He would dearly love to show a causal relationship between culture and imperialism, but cannot.他非常希望证明文化和帝国主义之间存在着某种因果关系, 但却做不到。