深入于

例句：

1. 1. The sun sets into the sea.
   太阳沉入海中。
2. 2. She stepped into the room and closed the door behind her.
   她走进房间，关上门。
3. 3. He was so tired that he fell asleep into his bed.
   他太累了，不知不觉地睡着了，睡在了床上。