one of the reasons____ which she got success in teaching is the application of multi-media填介词或副词

问题描述:

one of the reasons____ which she got success in teaching is the application of multi-media
填介词或副词

应该是填for,表示原因.
原句的意思是她在教学上取得成功的原因之一便是合理地运用多媒体技术.