16 What is the best title for this passage?
(A) Diverse Backgrounds of Immigrants.
(B) Key Findings about US Immigrants.
(C) Reasons for Becoming Immigrants.
(D) Rights and Obligations of Immigrants.

The United States has more immigrants than any other country in the world.
美國擁有的移民人數比世界上任何其他國家都多。

Today, more than 40 million people living in the US were born in another country, accounting for about one-fifth of the world’s migrants.
如今，居住在美國的居民中，有超過 4,000 萬人出生於其他國家，約占全世界移民人口的五分之一。

Also, the population of immigrants is very diverse, with just about every country in the world represented among US immigrants.
此外，美國的移民人口非常多元，世界上幾乎每個國家都有人民成為美國移民。

Pew Research Center regularly publishes statistical portraits of the nation’s foreign-born population, which include historical trends since 1960.
Pew研究中心定期發布美國外國出生人口的統計概況，其中包含自 1960 年以來的歷史趨勢。

These portraits provide more details on the US immigrant population.
這些統計資料提供了更多有關美國移民人口的詳細資訊。

The US foreign-born population reached a record 44.8 million in 2018.
2018 年，美國的外國出生人口達到歷史新高，為 4,480 萬人。

Since 1965, when US immigration laws replaced a national quota system, the number of immigrants living in the US has more than quadrupled.
自 1965 年美國移民法規取代原本的國家配額制度以來，居住在美國的移民人數已經增加超過四倍。

Immigrants today account for 13.7% of the US population, nearly triple the share (4.8%) in 1970.
如今，移民占美國總人口的 13.7%，幾乎是 1970 年 4.8% 的三倍。

However, today’s immigrant share remains below the record 14.8% share in 1890 when 9.2 million immigrants lived in the US.
然而，目前移民所占的比例仍低於 1890 年創下的歷史最高紀錄 14.8%；當時有 920 萬名移民居住在美國。

Most immigrants (77%) are in the country legally, while almost a quarter are unauthorized, according to new Pew Research Center estimates based on census data adjusted for undercount.
根據Pew研究中心利用經調整、修正低估情況的人口普查資料所做出的最新估計，大多數移民（77%）是合法居留在美國，而將近四分之一屬於未經授權的移民。

In 2017, 45% were naturalized US citizens, 27% of immigrants were permanent residents, and 5% were temporary residents in 2017.
2017 年，移民中有：45% 是歸化的美國公民、27% 是永久居民、5% 是臨時居民

Another 23% of all immigrants were unauthorized immigrants.
另外，所有移民當中有 23% 屬於未經授權的移民。

From 1990 to 2007, the unauthorized immigrant population was more than tripled in size – from 3.5 million to a record high of 12.2 million in 2007.
從 1990 年到 2007 年，未經授權的移民人口增加超過三倍，從 350 萬人增加到 2007 年創下歷史新高的 1,220 萬人。

By 2017, that number had declined by 1.7 million, or 14%.
到了 2017 年，這個數字減少了 170 萬人，也就是 14%。

There were 10.5 million unauthorized immigrants in the US in 2017, accounting for 3.2% of the nation’s population.
2017 年，美國有 1,050 萬名未經授權的移民，占全國人口的 3.2%。

The decline in the unauthorized immigrant population is due largely to a fall in the number from Mexico – the single largest group of unauthorized immigrants in the US.
未經授權移民人口的下降，主要是因為來自墨西哥的移民人數減少；墨西哥移民是美國未經授權移民中人數最多的單一群體。