foot是单数还是复数
foot是单数，foot的复数形式是feet；
foot
n. (人或动物的)脚，足;有…脚(或足的);有…只脚(的);用…脚(或足的);(袜子的)足部;
v. 走，踏;合计，结算（up），加（to），支付
He moved restlessly from one foot to another.
他的两只脚不停地倒替着。
It was the first time I had set foot on American soil.
It was the first time I had set foot on African soil.
那是我第一次踏上非洲大地。
I vowed never to set foot in the place again.
我发誓再不去那个地方了。
The country has been on a war footing since March.
自三月份起这个国家就准备要打仗。
She put her foot down and the car roared away.
她踩下油门，车子呼啸而去。