It is not known why yellow fever has not spread to Asia.

尚不清楚为什么黄热病未传播至亚洲。

youdao

This form of AIDS is found in West Africa, but has not spread much beyond that part of the world.

这种形式的艾滋病发现于西非，但没有传播到世界其他地区。

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This finding is important as it indicates that the virus has not spread beyond the members of this single extended family.

这一结果至关重要，因为它表明病毒的传播未超出该 单一大家庭的成员。

youdao

An operation to remove the cancerous cells can cure melanoma if the cancer has not spread.

VOA: special.2010.07.06

Fortunately for the industrialised world, the trend has not spread to other commodities yet.

BBC: Steel production

The bigger problem is that the success of central business districts has not spread to the poorer parts of America's cities.

ECONOMIST: The state of the cities

Critics complain that he has not spread patronage far enough beyond the Yadavs and Muslims, who constitute the core of his support.

ECONOMIST: India