Scientists call such markers "proxies" for the thing they actually want to measure — in this case, the geographic extent of the ice in the past.

科学家称这种标志物为“替代品”，代表他们真正想要测量的东西——在本例中，即在过去冰的地理范围。

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The national sport of Canada is ice hockey. They sometimes also call it "Canadian hockey". It is a popular game for both boys and girls all over the country.

加拿大的国家运动是冰球。有时它们也称作“加拿大曲棍球”。它是流行于全国男女老少的一项运动。

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What's more, the ice doesn't quit at the level of the soil. It's also below the surface in places that do occasionally get sunlight — a kind of lunar permafrost, the scientists call it.

冰会存在于一定土层。在偶尔能照到太阳的表面下，科学家把它叫做一种月球冻土。

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Since the beginning of the commercial revolution in the 14th century executives have built or lead their businesses in what scientists call the Holocene climatic epoch, a geologic time period that began at the end of the last ice age around 12, 000 years ago.

FORBES: Business in a Post-Holocene World