In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

(CNN) A submarine is joining the Mediterranean Sea search for the black boxes that could reveal what caused the crash of EgyptAir Flight 804. The aircraft disappeared from radar last week on a flight from Paris to Cairo. Searchers have recovered parts of the plane wreckage, including passengers' personal belongings, life vests, aircraft chairs and even body parts. But they're still scouring the Mediterranean for the plane's fuselage, and for the flight data recorder and cockpit voice recorder -- key pieces of evidence that would likely reveal what went wrong on the flight. Egyptian President Abdel Fattah el-Sisi announced the deployment of the submarine Sunday. It can reach a depth of 3,000 meters (about 9,800 feet), he said.Mourners at a Cairo mosque gather in memory of the plane's pilotEgypt uses submarine to hunt for flight data and cockpit voice recorders 
 Question:The jet had routine maintenance checks in _ before it left for Paris, the airline said.
Cairo

(CNN) With just two weeks until Congress is expected to leave town, the fate of roughly 700,000 young immigrants still hangs in the balance. And, it could be up to Senate Democrats now to decide whether they will make protections for the Deferred Action for Childhood Arrivals (DACA) program recipients a condition of their support for a must-pass spending bill or punt the issue to next year when they still have months to work it out. There's a whole host of issues that must be dealt with by the end of the year including reauthorizing a spying program, funding disaster relief and paying for the Children's Health Insurance Program, which has all sparked questions about whether Democrats will insist DACA also be included in that list of year-end spending priorities.Democrats have repeatedly called for a fix to the ending of the DACA programThe party may have the most leverage as part of their year-end negotiations 
 Question:The President had spoken favorably in September about DACA recipients and pushed _ to reach a deal, but in recent weeks ne has taken to hardline rhetoric on illegal immigration and blaming Democrats for crime.
Congress

Washington (CNN) -- President Barack Obama used a Memorial Day ceremony to say it is time for America to properly welcome home Vietnam veterans and show them and their families the respect and gratitude they deserved but didn't receive decades ago. "You came home and sometimes were denigrated when you should have been celebrated," Obama said beneath a scorching sun at the Vietnam Veterans Memorial. "It was a national shame, a disgrace that should have never happened. That's why here today, we resolve that it will not happen again." The event, which launched a 13-year Vietnam War 50th anniversary commemoration, was the culmination of a day of somber events on the annual holiday honoring America's war dead.NEW: President Obama calls the denigration of Vietnam veterans a "national shame""America will be there for you," Obama tells veterans and their familiesMemorial Day launches a 13-year commemoration of the Vietnam War's 50th anniversaryObama lays a wreath to the fallen at Arlington National Cemetery 
 Question:This year marks the 50th anniversary of the _ deploying a significant military presence in Vietnam.

America