Which of these rivers has the shortest link? Yukon, Rio Grande, Volga or Niger. At about 1,900 miles, the Rio Grande is the shortest river on this list.

以下哪条河流最短？育空河、格兰德河、伏尔加河还是尼日尔河？长约1900英里的格兰德河是上述名单最短的河流。

The Rio Grande forms a natural border between Mexico and the United States and it's at that border where there's been a dramatic increase this year in the number of people trying to cross into the U.S. American critics call the situation a crisis. The Biden Administration has called it a challenge.

格兰德河是墨西哥和美国之间的天然界河，而今年试图越过这条界河进入美国的人数急剧增加。美国评论家将这种情况称为危机。拜登政府称这是挑战。

One of the reasons behind the increase is a change in U.S. law.

越境人数增加背后的原因之一是美国法律的改变。

Under the Trump Administration last year, U.S. border officials were allowed to turn away people who illegally entered America out of concerns they could bring new cases of coronavirus. Under the Biden Administration this year, children who are caught illegally crossing the border are allowed to stay in the U.S. while their cases for immigration are reviewed.

去年，特朗普政府授权美国边境官员拒绝非法进入美国者，因为他们担心这些人可能导致冠状病毒新增病例的出现。而今年在拜登政府的领导下，因非法越境而被捕的儿童，可在其移民案件被审查期间留在美国。

There are many reasons why people try to enter America. Violence and poverty in their home countries, problems made worse in Central America by the coronavirus pandemic, new opportunities in the United States. And while the Biden Administration says it's trying to develop more helpful programs for immigrants, critics say the government's taking too long to get control of the situation at the border.

人们试图进入美国有很多原因。比如本国的暴力和贫困、因冠状病毒疫情而恶化的中美洲问题以及美国的新机遇。虽然拜登政府表示，他们正在努力为移民制定更为有益的计划，但批评人士称，政府在控制边境局势方面花费了太长时间。

Meanwhile, U.S. Border Control agents are struggling to process those who are crossing legally and to stop those who are crossing illegally. At the beginning of the week, there were about 4,200 unaccompanied children in the custody of U.S. Border Control. That's 1,600 more children there were during the border crisis in 2019.

与此同时，美国边境管制机构正在努力处理那些合法越境的人员，并阻止非法过境者。本周初，有约4200名无人陪伴的儿童处于美国边境管制局的关押之中。这比2019年边境危机时羁押的儿童还要多1600名。

来源：CNN