The World Health Organisation concurred, saying that if unchecked, swine flu could affect almost a third of the population – 2 billion people.

世界卫生组织对此持相同看法，并表示如果不对猪流感进行有效防控，那么感染人群将会达到世界人口的三分之一——二十亿。

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This damage causes them to grow into abnormal lumps or tumours and spread around the body disrupting its normal processes and eventually--if unchecked--causing death.

这些破坏使健康细胞长成异常的肿块或肿瘤，扩散至全身，扰乱正常的生理过程，如不加以遏止，最终将导致死亡。

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If left unchecked, weeds will flourish.

如果不加遏制，杂草就会疯长。

《柯林斯英汉双解大词典》

But more red tape and higher taxes, if unchecked, risk clipping the wings of Britain's high-flying firms.

ECONOMIST: A lost opportunity

The ultimate result, if unchecked, is depression and economic anarchy.

FORBES: Fact and Comment

Its initial focus is on five global issues that, if unchecked, could bring the world to its knees: climate change, water scarcity, pandemics, nuclear proliferation and Middle East conflict.

FORBES: A Minute with Jeff Skoll on Technology and Global Social Change