lest

We crept into the room quietly lest we should wake the sleeping baby.

(Chinese) 我们悄悄溜进房间，生怕吵醒熟睡的婴儿。

He checked his notes one last time lest he forget any important details.

(Chinese) 他最后检查了一次笔记，以免遗忘任何重要细节。