英语听力精选进阶版 133316（在线收听） |
Secrets of the plague Vocabulary rarely encountered not often met or come into contact with devastating destructive and harmful sparked caused to start fleas tiny jumping insects which feed on the blood of animals and humans fragments small, incomplete pieces of victims people who had died of the disease strains versions of the disease immune systems our body's natural defence mechanism adapted changed and evolved to be able effectively to fight pathogens small organisms that cause diseases |
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