One female panda usually has only one baby, and it is not easy for wild pandas to have twins anyway.

一只雌性熊猫通常只有一个孩子，而且野生熊猫要生双胞胎也不容易。

youdao

Only one baby survived the terrible car crash.

在那次可怕的撞车事故中，只有一个婴儿生还。

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Female anteaters usually give birth to only one baby a year. It rides on the mother's back for several weeks after it is born.

雌性食蚁兽通常一年生一个崽子。出生后的几周内，它都骑在妈妈的背上。

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Here is the song "Baby I'm a Fool" from her second album, "My One and Only Thrill."

VOA: special.2009.10.30

And even here in this captive breeding program, an invasive insect has meant that in the past two years, only one baby tortoise, named Genesis, has hatched successfully.

NPR: Common Intruders Threaten Galapagos Species

The mothers only have one baby a year and must wait until next year to breed again.

BBC: NEWS | UK | Scotland | Highlands and Islands | Baby bats hit by cold, wet summer

Only one in three Iraqi women breast-feeds her baby in the first six months of life.

ECONOMIST: Water