And bubonic plague, spread by rat fleas, is normally preceded by the death of hordes of rats (only then do the fleas opt for humans). Yet no one in 1348 recorded this.

黑死病由鼠蚤传播，在此之前通常都有大批的老鼠死亡(只有在这时跳蚤才选择人类作宿主)，但在1348年没有人记录下这些。

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Rat-fleas communicate a disease to man.

鼠蚤会把疾病传染给人。

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