她潜入湖中静止的水里。

She dived into the ___still water of the lake.

空气如此静止，以至于树上的叶子都没有动。

The air was so ___still that not even the leaves on the trees were moving.

在修道院遗址的脚下是一个池塘，宽阔而静止，在阳光下平滑。

At the foot of the monastery's ruins was a pool, wide and ___still, and smooth in the sunlight.