a pair of shoes一双鞋
[观察] My mother bought me two pairs of shoes.我妈妈给我买了两双鞋。
A pair of shoes is under the bed.床底下有一双鞋。

[探究] a pair of...意为“一双/副/对..…..…”，如:a pair ofglasses一副眼镜。名词shoes, glasses, clothes,trousers等作主语时,谓语动词必须用_复数__形式。但是，如果这些名词被a pair of 修饰时，谓语动词用单数
形式。

1.这就是她穿红色衣服的原因。
That is why she is wearing red
2·我认为这位女士肯定感觉有点儿紧张。
i think the woman must feel a little bit stressed.
3·红色与白色搭配相宜。
Red and white are a good match