摘要：a pair of与复数名词连用时,同一个从句中的动词要用单数。请看下面的实例:

a pair of一双，一对，两个

a pair of与复数名词连用时,同一个从句中的动词要用单数。请看下面的实例:

Under his arm was a pair of shoes which he had bought from the shop a few days previously.

他腋下夹着几天前从商店买的一双鞋。

A pair of glasses costs quite a lot these days. 现时一副眼镜值很多钱。

A pair of oxen, yoked together, was used.

把两头牛用轭套在一起使唤。

A pair of jewelled earrings will liven up this dress without detracting from its simplicity.

一对宝石耳环会让这件礼服更出彩而又不失简洁。

A pair of pretty, faded pink antique curtains was the starting point for the room's colour scheme.

一幅漂亮的褪色仿旧粉色窗帘是房间色彩搭配的基调。

A new pair of shoes brings more happiness to a child than a new car brings to a grown-up.

一双新鞋给儿童带来的快乐甚于一辆新车给成年人带来的快乐。

On the mantelpiece are a pair of bronze Ming vases.

壁炉台上是一对明代的青铜花瓶。（用了复数，比较例外）

《柯林斯高阶英汉双解学习词典》

但是, a pair of之后的代词以及定语从句中的谓语动词则常用复数形式:

I like this pair. How much are they?

我喜欢这一双。(它们)卖多少钱?

I like this pair. How much is it?

我喜欢这一双。(它)卖多少钱?（也可以用单数）

She went to the wardrobe, chose a pair of shoes, put them on and leaned back in the chair.

她向衣橱走去,选了一双鞋,穿在脚上,然后依在椅背上。

He wore a pair of earphones, which were plugged into a tape-recorder.

他戴着一副耳机，耳机连在录音机上。

他腋下夹着几天前从商店买的一双鞋。

应当注意,当a pair(of)作“两个人”“一对夫妇”解时,其谓语动词通常用复数,但有时也可用单数:

A pair of teenage boys were smoking cigarettes

两个十来岁的男孩正在吸烟。

壁炉台上是一对明代的青铜花瓶。

The happy pair is/are going to Spain after their wedding.

这对愉快的新婚夫妇在婚礼后将去西班牙。

来源：翅膀英语一点号