她有一双大眼睛和一张小嘴巴用英语怎么说

"She has big eyes and a small mouth" 可以用英语表达为 "She has a pair of big eyes and a small mouth"。

"Pair" 是一个名词，表示 "两个相对的东西"。在这里，它表示 "一双"，与 "big eyes" 一起构成了一个完整的描述。

一些英文例句和中文翻译如下：

She has a pair of big, brown eyes. (她有一双大而棕色的眼睛。)
He has a pair of sharp eyes. (他有一双敏锐的眼睛。)
They are a pair of siblings. (他们是一对兄弟姐妹。)