foot的复数形式是什么

例句：

stamped her foot again.

她又跺了跺脚。

d called to the children from the foot of the stairs。

戴维在楼梯下面喊孩子们。

nds stood at the foot of the bed, looking at her with serious faces.

朋友们站在床脚处，神情严肃地看着她。

4.I tried to reach the foot brakes but I couldn't.

我试图去够脚刹，但是没能踩到。