distractors: kind set group
sentence: A group of graduates got together to visit their old university professor.The conversation soon turned into  complaints  about stress in work and life.Offering his  guests  coffee,the professor went to the kitchen and  returned  with a large pot of coffee and a  [MASK]  of cups--porcelain,plastic glass,crystal,some plainlooking,some expensive,some exquisite ,telling them to  help  themselves to the coffee.