禽流感病毒具有高度物种特异性，但偶尔也跨越物种屏障，感染人类。
Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans.
禽流感病毒具有高度物种特异性，但偶尔也跨越物种屏障，感染人类。
Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans.
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