Of all the blue holes in the world, Sansha Yongle Blue Hole in the South China Sea is now the deepest.

目前在世界上所有的蓝洞中，中国南海的三沙永乐蓝洞是最深的。

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You might ask why The Great Blue Hole has such an unusual color.

你兴许要问，为什么大蓝洞有如此不同凡响的色彩。

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Or the great blue hole, an underwater sinkhole off the coast of Belize.

或者这个巨大的蓝色坑洞，伯利兹海岸一个水下天坑。

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More advanced divers will be lured to the challenge of the Blue Hole dive site just north of town.

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The Hubble Space Telescope recently spied a cluster of young blue stars surrounding a rare mid-weight black hole that suggests the black hole was once at the center of a dwarf galaxy.

MSN: Rare Black Hole Survives Galaxy's Destruction

There is a stamp club, and a minigolf course, where the obstacle on the first hole isn't a windmill but a blue mail collection box.

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