TASK DEFINITION: You will be given three sentences. Read them, then identify a noun phrase (person, place, or thing) or event that is shared between all three sentences. As the output, write the span of the text corresponding to that phrase in each sentence. Keep the order of the sentences, that is, your answer should look like: 1: *a phras from sentence 1e* 2: *a phras from sentence 2* 3: *a phrase from sentence 3*
PROBLEM: 1: ( CNN ) On April 20 , 2010 , a final cement seal of an oil well in the Gulf of Mexico failed , causing what has been called the worst environmental disaster in U.S . history and taking the lives of 11 rig workers . 2: The federal government estimated 4.2 million barrels of oil spilled into the Gulf , but BP argued in court that it was much lower . 3: April 20 marks 5 years since the BP oil spill .

SOLUTION: 1: the worst environmental disaster in U.S . history 2: 4.2 million barrels of oil spilled into the Gulf 3: the BP oil spill

PROBLEM: 1: Shortly after the charges were announced , Bergdahl 's attorneys released a lengthy statement that includes a letter sent to Milley earlier this month outlining their defense of the soldier . 2: The statement includes a two-page accounting from Bergdahl of his time in captivity , in which he recounts months spent chained to a bed , then further years spent chained on all fours or locked in a cage . 3: Attorney releases Bergdahl 's account of his time as a prisoner .

SOLUTION: 1: Bergdahl 2: Bergdahl 3: Bergdahl 's

PROBLEM: 1: Another aviation analyst , David Soucie , said the quickness of the descent shows something went wrong , but also that the plane was not out of control . 2: O'Brien pointed out the known details of the crash -- a rapid descent , no radio call and a flight that continues into the mountains -- are not part of a  typical emergency scenario .  3: CNN aviation analyst says this is not a typical emergency incident , but all possibilities are part of probe .

SOLUTION:
1: aviation analyst 2: O'Brien 3: CNN aviation analyst