人口密度过高会给交通和住房带来压力。Rénkǒu mìdù guò gāo huì gěi jiāotōng hé zhùfáng dài lái yālì.Excessive population density will put pressure on transport and housing.
水的密度比油大,所以油浮在水上。Shuǐ de mìdù bǐ yóu dà, suǒyǐ yóu fú zài shuǐ shàng.Water is denser than oil, so oil floats on water.
这个城市的建筑密度很高,绿地很少。Zhège chéngshì de jiànzhù mìdù hěn gāo, lǜdì hěn shǎo.This city has a very high building density and little green space.