His fear of dogs traces back to a childhood experience.

他对狗的恐惧可追溯到他在孩提时代的一次经历。

His family traces back to the Norman Conquest.

他的家世可追溯到诺曼人征服英国的时代。

His father claims to be able to trace the family back to many centuries ago.

他父亲声称能把家世追溯到许多世纪之前。

I think we can trace the fever back to that long cold swim that she looked against our advice.

我认为她是因为不听我们的劝告而去那次长时间的冷水游泳才发烧的。

The rumour has been traced back to him.

那谣言经追查是他造的。