Definition: In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
Input: Article: "A child is dying---out of breath!" I had just begun my working day in the city, when those words came through the radio of the police car I was driving. I turned on the red lights and siren  and drove off as fast as I could. "Just my luck!" I thought. I did not know this city well and my first call of the day was a life-and-death sudden happening, several kilometers away.     I got to the house. A mother, filled with fear, handed me her baby, his face already blue. Was I too late? Dear me!      I did what I had been taught to do in such a serious condition. A small thing flew out of the baby's mouth onto the floor. It was a button. Thanks heavens! The holes in it let a little air through.       The doctor rushed into the room. He had with him an oxygen  bag.        The child began to cry at the top of his voice, turned red and started to look for his mother. He was angry but saved. 
 Answer: the button happened to have holes in it
