obsolescence

例句：

1. 1. The old model is now completely obsolete.
   这个旧模型现在已经完全过时了。
2. 2. The technology has been obsolete for many years.
   这项技术已经过时很多年了。
3. 3. The obsolete design was replaced by a more modern one.
   那个过时的设计被更现代的设计所取代。