Population: HSK 6 人口：HSK 六级

许多移民改了名字。

Xǔduō yímín gǎile míngzi.

Many of the immigrants changed their names.

美国是一个移民国家。

Měiguó shì yí gè yímín guójiā.

America is a land of immigrants.

河水慢慢地向东流动。

Héshuǐ mànmàn de Xiàngdōng liúdòng.

The river water flows slowly to the east.

那辆流动图书车每周都来。

Nà liàng liúdòng túshū chē měizhōu dōu lái.

That mobile library van comes every week.

水的密度比油大。

Shuǐ de mìdù bǐ yóu dà.

Water is denser than oil.

空气的密度是多少？

Kōngqì de mìdù shì duōshǎo?

What is the density of air?

工地上的劳动力不够了。

Gōngdì shàng de láodònglì búgòule.

There isn't enough manpower at the construction site.

机器能代替一部分劳动力。

Jīqì néng dàitì yíbùfen láodònglì.

Machines can replace part of the manpower.

养老是社会的一个大课题。

Yǎnglǎo shì shèhuì de yí gè dà kètí.

Caring for the elderly is a big problem for society.

海岛四季如春，适合养老。

Hǎidǎo sìjìrúchūn, shìhé yǎnglǎo.

The island has spring-like weather all year, which makes it good for retirement.

蝴蝶的寿命短。

Húdié de shòumìng duǎn.

The life span of a butterfly is short.

合理地喂狗可以延长宠物寿命。

Hélǐ de wèi gǒu kěyǐ yáncháng chǒngwù shòumìng.

If you feed your dog properly, you can increase his lifespan.

人均用水量每年都在下降。

Rénjūn yòng shuǐliàng měinián dōu zài xiàjiàng.

Water use per person falls every year.

这顿饭人均不到一百块钱。

Zhè dùnfàn rénjūn búdào yìbǎi kuài qián.

This meal cost less than a hundred yuan per person.