add to|added to

雪上加霜的是，我的右手骨折了。

To ___add ___to the bitterness, I had my right hand broken.

同事们的笑声只会加剧她的尴尬。

Her colleagues' laughter only ___added ___to her embarrassment.

不健康的食物和繁忙的日程会增加学生的压力。

Unhealthy food and a busy schedule can ___add ___to a student’s stress.