This is the 4365th most frequent Chinese word.
忙於
"Busy with" or "occupied with."
The word '忙於' is used here to indicate being occupied with a specific task, 'preparing'.
她忙於準備明天的報告。
She is busy preparing for tomorrow's presentation.
In this sentence, '忙於' conveys that the subject is engaged in addressing work-related challenges.
他忙於應付工作上的挑戰，沒有時間休息。
He is busy handling challenges at work and has no time to rest.
Here, '忙於' denotes the subject's involvement in acquiring knowledge and skills.