a (an)/one.导航词义：一个

1. a (an):indef. art. 一个.通常用于单数可数名词之前，泛指某类人或事物中的一个。

My friend needs a bilingual dictionary.

我的朋友需要一本双语词典。

Would you like a sandwich?

要来份三明治吗？

There is a bird sitting in the tree.

树上卧着一只鸟。

2. one:num. 一，一个.强调数量的概念，说明是一个而不是两个或三个。

One million means a lot to me.

一百万对我来说是个大数目。

Plant one tree per hour.

每小时种一棵树。

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1·I'd like an explanation.

我想要一个解释。《柯林斯英汉双解大词典》

2·An ambulance drove past.

一辆救护车驶了过去。《柯林斯英汉双解大词典》

3·An owl hooted nearby.

一只猫头鹰在附近啼叫。《牛津词典》

4·An argument ensued.

紧接着的是一场争论。《牛津词典》

5·I want an apple.

我要一个苹果。《柯林斯英汉双解大词典》

6·This recipe is an adaptation of an old favourite.

这个食谱是一个传统名食谱的改编。《柯林斯英汉双解大词典》

7·The exam consists of an essay and an unseen translation.

考试包括一篇作文和一篇即席翻译。《牛津词典》

8·Hay fever is an affliction that arrives at an early age.

花粉热是一种早年易患的病。《柯林斯英汉双解大词典》

9·An exultant party leader said: He will be an excellent MP.

一位面带欢欣的政党领导人说：“他会成为一名出色的议员。”《柯林斯英汉双解大词典》

10·An Olympic gold medal can lead to untold riches for an athlete.

一枚奥运金牌能为一名运动员带来数不尽的财富。《柯林斯英汉双解大词典》