Both oil and gas are less dense than water, so they generally tend to rise upward through water-saturated rock and sediment.

石油和天然气的密度都比水小，所以二者通常会浮在被水浸泡的岩石和沉积物的表层。

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One type of pattern was of a specific density and was to be classified as dense, while the second type of pattern could vary in density, but was always less dense than the first one.

一种图案具有特定的密集度，被归为“密集”类，另一类图案的密集程度不同，但都比第一种的密集程度低。

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Less dense substances move upwards to form a crust.

密度小的物质向上浮动并形成一层皮。

《牛津词典》

Magnesium is a liquid but it's less dense than magnesium chloride.

镁是液体,但是它的密度比氯化镁要小。

麻省理工公开课 - 固态化学导论课程节选

The other three whose masses are known are less dense, so presumably have more hydrogen.

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That would have made the Atlantic's upper layers less dense, so less liable to sink.

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P-1 is the second exoplanet that is much bigger and less dense than theory predicts.

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