The platypus (Ornithorhynchus anatinus) is one of only two mammals, the other is the echidna (spiny anteater) that lays eggs.

鸭嘴兽（Ornithorhynchus anatinus）是仅有的两种卵生的哺乳动物之一，另一种为食蚁兽（spiny anteater），它产卵。

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Now, the island is one of only a handful of lesser flamingo breeding colonies in the world.

目前该岛是世界上为数不多的小火烈鸟繁殖基地之一。

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Air India is one of only a handful of large airlines without a big domestic feeder airline.

印度航空是少数几家没有大型国内航空支线的大型航空公司之一。

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For a time he was one of only three doctors,and the only surgeon, at a huge hospital in Kinshasa.

VOA: special.2009.02.23

It's one of the only compounds, there's only I think three, where the density actually goes down when it freezes.

它是我见过的，唯一一个，在降温时密度下降的化合物。

麻省理工公开课 - 固态化学导论课程节选

I only had one year left of university, it was too late to, to change from... to a too different subject,

我还有一年就要毕业，所以已经来不及换专业了，

换专业的理由 - SpeakingMax英语口语达人

The trust's eye unit is believed to be one of only 10 national eye retrieval centres.

BBC: Hospital's plea for organ donors

You can buy it in the Pebble Beach pro-shop, one of only two retail outlets.

FORBES: The World's Best Jigsaw Puzzles

Constructed in 1914, it is one of only 200 vessels in the National Historic Fleet.

BBC: Northern Ireland