predecessor block

例句：

1. 1.The computer's processor has a predecessor block that stores the operating system.
   计算机的处理器有一个存储操作系统的前驱块。
2. 2.The scientist used a predecessor block to study the chemical reaction.
   科学家使用一个前驱块来研究化学反应。
3. 3. The new software had a predecessor block that allowed for easy updates.
   新软件有一个前驱块，可以方便地更新。