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

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.
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.

xLtJz!hH1-R&op+nDVsMSJFa&8Tn(;N!k8CMTacek 来源:可可英语 //www.utensil-race.com/broadcast/202104/626329.shtml