密度

nà ge guó jiā de rén kǒu mì dù wéi měi píng fāng yīng lǐ rén

那个国家的人口密度为每平方英里700人。

The population density of that country is 700 per square mile.

é luó sī rén kǒu mì dù dī

俄罗斯人口密度低。

Russia has a low population density.

lǎo nián rén měi tiān xū yào duàn liàn yǐ bǎo chí gǔ gé mì dù

老年人每天需要锻炼，以保持骨骼密度。

Old people need to exercise every day to maintain bone density.

shuǐ de mì dù bǐ kōng qì de mì dù yào dà xǔ duō

水的密度比空气的密度要大许多。

Water has a much greater density than air.

zěn me cè liáng hǎi shuǐ de mì dù

怎么测量海水的密度？

How to measure the density of seawater?

shuǐ yín de mì dù dà yú shuǐ de mì dù

水银的密度大于水的密度。

Mercury has a much greater density than water.