So suburb-ringed cities with low overall densities are much less efficient than those that are tightly-packed.

所以，总体密度低的郊区环线城市的效率要比那些紧密的城市低多。

You've probably heard of some of these. One is low density lipoprotein — also known as LDL cholesterol.

你可能听说过其中的一些。一种是低密度脂蛋白——也被称为低密度脂蛋白胆固醇。

They discovered that patients with depression had a lower density of synapses than healthy people of the same age.

他们发现，抑郁症患者的突触密度低于同龄的健康人群。

But, despite their length, tails are incredibly low density, as low as a few hundred atoms per cubic centimeter.

但是，尽管尾，它的密度却低得令人难以置信，低到每立方厘米只有几百个原子。

They live in low densities, they're extremely well camouflaged, and when they move, they stay low to the ground.

它们数量稀少，又极善于伪装，在移时，身体会尽量贴近。

First, there's Looser zones, which are bands of low bone density that form on the surface of the bone.

首先，会有Looser区，即在骨表形成的低密度带。 小编注：Looser区以瑞士外科医师Emil Looser命名。

It was also very low density, just what you'd expect for a loosely bound rock pile.

它的密度也低，正如你所想象的的松散的岩石堆。

Wyoming has the lowest population overall, but Alaska, which is by far, the largest state has the lowest population density.

蒙大拿州总体上人口最少，但阿拉斯加是远远最大的州，人口密度最低。

These felines live at very low densities, and between two potential mates may be dozens of kilometers of harsh terrain.

这些猫类生物的密度非常低，可能几十公里的恶劣形才能遇到一个潜在的伴侣。

Objects with lower density, like stuff that's made of organic materials, will allow more of the lower-energy X-rays to pass through.

低密度的东西，像有机材质的东西，会让低能级的X射线穿过。

The comet has a very low density, similar to rubble-pile asteroids, so it was expected that the surface would be soft.

彗星的密度非常低，类似于碎石堆积的小行星，所以它的表应该会是柔软的。

Meanwhile, lighter substances with lower density, like plasma, move to its center.

与此同时， 密度较低的较轻物质，如等离子体，会移到它的中心。

Let's start with a fun city that has a pretty low population density.

让我们从一个人口密度低的有趣城市开始。

Whereas this is much squishier, this is low density polyethylene.

虽然它更柔软， 但它是低密度聚乙烯。

However, even people who exercise often can have low bone density.

然而，即使是经常运的人，骨密度也会偏低。

Hargett was surprised when the doctors told him that he had low bone density.

当医生告诉他他的骨密度低时，Hargett 感到惊讶。

Then, you go to medium density, low density and higher density again.

然后，您再次进入中密度、低密度和更高密度。

Small city, we have low density, make the design more romantic.

小城市，我们低密度，让设计更浪漫。

Northern forests offer the lowest human density of any tiger habitat, and the most complete ecosystem.

北方森林是所有老虎栖息中人类密度最低的， 也是最完整的生态系统。

In short, neither high population density nor low population density automatically makes a country rich or poor.

简而言之，人口密度高或人口密度低都不会自导致一个国家富裕或贫穷。