Two dollars for one pair and three dollars for two pairs.

一双两美元，两双三美元。

The trapezium has one pair of parallel sides.

梯形有一对平行边。

I early want one pair.

我早就想要一副了。

Sorry, Greg, I've only one pair of hands!

对不起，格雷格，我不能干那么多活，我只长了一双手！

I have several coats but only one pair of trousers.

我有几件上衣，但只有一条裤子。

The scheme is efficient and only needs one pair operation.

方案仅需要一次双线性对运算，实现快速。

One wallet and one pair of shoes, one color, all seasons.

一年四季，我们都是一个钱包，一双鞋，一种颜色。

One wallet and one pair of shoes one color for all seasons.

皮夹和鞋子永远是同款颜色。

Hold on, lad, I am going to buy only one pair!

停一停,孩子,我只买一双!

He has one pair of glasses on the top of his head. And another pair on a piece of cord around his neck.

一副眼镜支在他的脑门上，还有一副用绳子挂在他的脖子上。