单选题 My parents moved out of their old home sometime last year after they had celebrated their 50th year there.
【正确答案】 A
【答案解析】名词辨析。此句中的year意为“年”,而A.anniversary周年纪念(前面需用序数词);B.years old岁(指年龄);C.age年龄,使用年限,时代;D.wedding婚礼,婚宴;因此A为答案。