周年纪念

例句：

1. 1. We celebrated our 50th anniversary last month.
   我们上个月庆祝了我们的五十周年纪念。
2. 2. The couple has been together for 30 years and is celebrating their 40th anniversary.
   这对夫妇在一起已经30年了，正在庆祝他们的第40个周年纪念。
3. 3. They held a party to mark the 10th anniversary of their wedding.
   他们举行了一个派对来纪念他们的婚礼十周年。