她在给孩子的衬衫扣扣子。

She is ___buttoning her child's shirt.

她不停地按电梯按钮，可门就是不开。

She kept ___pressing the elevator button, but the door wouldn't open.

她匆忙地扣上外套的扣子，以免迟到。

She hurriedly finished ___buttoning her coat to avoid being late.