engrossed in thought

• 陷入沉思之中

engrossed in thought的用法和样例：

例句

1. She was lost in reflection on her future.
   她为自己的未来而陷入沉思之中。
2. The greatest of all pleasures consists in the contemplation of truth.
   所有快乐中最伟大的快乐存在于对真理的沉思之中。