2[er]是一个自然数，同时也是1和3之间的正整数，也是偶数。2有很多数学性质，如果一个整数能被2整除，那个数就是偶数，反之则是奇数。2是最小的质数（也叫素数），也是的偶质数，只有1、2两个因数，是一个有理数，也是一个双数。2也是Heegner数。

2用英文怎么写？

Two

英 [tuː]  美 [tuː]

num.二

复数： twos

two的双语例句

1.The typical family structure of Freud's patients involved two parents and two children 

弗洛伊德的病人的典型家庭结构是父母二人和两个孩子。

2.Half of four is two. 

四的一半是二。

3.Four plus two equals [ is] six. 

四加二等于六。

4.They enjoyed a romantic dinner for two at one of their favourite restaurants. 

他俩在他们最喜欢的一家餐馆里吃了一顿浪漫的二人晚餐。

5.Two plus three makes five.; Two and three is five. 

二加三等于五。

two的常见句型

用作数词 (num.)

1.Two plus five is seven.

二加五等于七。

2.All things invariably divide into two.

事物都是一分为二的。

two的词汇搭配

in two 分开 

put two and two together 推断

in twos and threes 三三两两, 零零星星

fall between two stools 两头落空 

number two 第二位的 

one or two 一两个

between two fires 左右为难 

two layer 双层的 

make two bites at a cherry 过分小心 

two ply 两层的(双重的)

two pulse 双脉冲 

two circuit 双回路的 

two address 二地址的 

two stage 两级的

two dimensional 二维

two position 二位置的 

kill two birds with one stone 一箭双雕 

have two strings to one's bow 有两手准备 

two stroke 二冲程的 

two phase 双相的

two的真题例句

1.After making a stop for a few hours at a British station on the edge of Antarctica, the two workers were flown to the southernmost Chilean city of Punta Arenas.

2019年6月四级真题（第二套）听力 Section A

2.As I sat blocked and clueless for two solid days, I momentarily wondered if I couldn't just call an expert on the subject matter which I was tackling, or someone who took the class previously, to get me going.

2017年12月四级真题（套）阅读 Section B

3.But these waterways seem minute in comparison to the world's two lengthiest rivers—the Nile and the Amazon.

2018年6月六级真题（套）听力 Section B

4.But when two H-bots became imperiled, the robot choked 42 percent of the time, unable to decide which to save and letting them both.

2017年12月六级真题（第二套）阅读 Section C

5.A rethink is required - and as a new approach starts to become apparent, two ideas stand out.

2017年高考英语江苏卷 阅读理解 阅读C 原文

6.A strong link is found between two species when a predator sticks to one prey species.

2019年高考英语天津卷 阅读理解 阅读C 题设

7.In France, shareholders who hold onto a company investment for at least two years can sometimes earn more voting rights in a company.

2019年考研真题（英语一）阅读理解 Section Ⅱ

8.Indeed, predictions of such a society have been around for two decades but have not yet come to fruition.

2013年考研真题（英语二）完形填空 Section Ⅰ