percent什么意思

如何用英语表达分数和百分数？

学习用英语表达分数和百分数，首先需要了解一些特殊表达：
1/2: one half (口语中常用 "a half")
1/4: a quarter / one quarter / a fourth
3/4: three quarters / three out of four / three fourths
接下来，让我们一起学习其他分数的表达方式：

1. 用基数词和序数词表达
英语中分数的表达通常结合基数词和序数词，分子用基数词，分母用序数词。
分子为1:
1/3: one third / a third
1/10: one tenth
1/100: one hundredth
分子大于1时，分母序数词用复数形式:
2/3: two thirds
3/10: three tenths
5/7: five sevenths
99/123: ninety-nine one hundred and twenty-thirds

2. 使用介词 "in", "out of", "over"
5/7 除了 five-sevenths，也可以用 five in seven，five out of seven 或 five over seven 表示。
复杂分数常用 "over" : 317/509 读作 three hundred and seventeen over five hundred and nine.
例句: Ninety-nine people out of a hundred, if they were asked who first found America, would answer Columbus. (如果要问是谁首先发现美洲，一百个人中有九十九个会回答是哥伦布。)

3. 带分数的表达
整数和分数之间用 "and" 连接:
2 1/2: two and a half (注意: 1/2 不用基数词加序数词)
4 3/5: four and three-fifths
1 5/9: one and five ninths
3/4 hour, 7/10 mile 可以说 three quarters of an hour (三刻钟), seven tenths of a mile (十分之七英里).

4. 百分数的表达
使用 "percent"
1%: one percent / a percent
75%: seventy-five percent
43%: forty-three percent
25%: twenty-five percent
11.3%: eleven point three percent
45%: forty-five percent
0.16%: zero point one six percent
百分数后接名词时，有时用介词 "of", 有时不用：
40% (forty percent) of the students (40%的学生)
a 90% (ninety percent) chance (9成的把握)
区别: 接 "of" 时, "percent" 是名词，表示整体中的一部分; 不接 "of" 时，"percent" 是形容词，不表示整体与部分的关系.

5. 用 "part" 表达
"part" 有 "...分之一" 的意思, 分子大于1时，"part" 用复数.
常见结构:
"基数词 + part(s) + in + 基数词": five parts in one thousand (千分之五)
"基数词 + part(s) + per + 基数词": one part per million (百万分之一)
百分之一除了说one (a) hundredth，更常用 one percent 或 per cent.
例句:
Our bodies are 65 percent water. (我们人体含65%水分。)
Seventy-five percent of the earth's surface is covered by water. (地球表面的75%被水覆盖着。)

English department 的 85% students 都是女生。

英语系85%的学生是女生。

air 的仅有 1/5 都是 oxygen．

氧气只占空气的1／5。