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: Mr. Black was very forgetful. Each time when Mrs. Black wanted her husband to do something, she had to tell him again and again not to forget it. Once Mr. Black was asked to post a letter, " Do remember to put it into the letter box on your way to work." The wife said. " This time I won't forget." Mr. Black said to his wife. "I will hold the letter in my pocket." "Oh, my dear, you may go now. Please come back early." Mrs. Black said. As Mr. Black was shown out, he felt as if his wife touched him affectionately   on the back. Hand in his pocket, Mr. Black walked slowly down the street. Soon a man caught up with him from behind and smiled at him, "Don't forget to post the letter." Mr. Black was wondering how the man knew he had a letter to post. Then a girl passed him and turned to smile at him, too."Now be sure to post the letter," the girl said. Mr. Black was even more puzzled, "Why are they smiling at me? And how do they know I'm going to post a letter?" he thought to himself. 
 Answer: Mrs. Black hoped her husband wouldn't post the letter in a wrong place
