a
音标发音
- 英式音标 [ə; eɪ]
- 美式音标 [ə; e]
- 英式发音
- 美式发音
基本解释
- art.一(个);每一(个);任一(个)
- n.英语字母表的第一个字母;学业成绩得优者;表示“最好”的符号
用法辨析
- 通常来说,a 是用在以辅音开首的词前面,an 是用在以元音开首的词前面;
- 可数名词前面用 a(或 an),不可数名词前面不可用a(或 an),如可以说 a healthy boy,却不可以说 a health;
- 在特定情况下,a(或 an)可以用在复数形式前面:习语中有a few (books),a great many (books)等表示方法。在表示时间或款项的短语前面,如 a further five minutes。在若干在形式上是复数而在意思上是单数的单词前面,如 a barracks,a links。在美国口语中,如 a good ways,a long ways;
- a(或 an)有时有“一个而不是那所要的一个”的意思。a 也有“任何一个”的意思。I got a letter indeed,but it was from a friend. 事实上,我收到了一封信,但只是一个朋友的来信。I wanted to read a book,I did not care whether it was a history,a novel,or a biography.
- a 与 few 搭配使用时,few 是“很少”,有“几乎没有”的意思。a few 是“若干”,有“颇有几个”的意思。注意,only a few 却等于 few,也是“很少”的意思。
英汉例句
- Liver and kidney are particularly rich in vitamin A.
肝脏和肾脏富含维生素A。 - Details are available from the Hon. Sec. A.R. Bushby.
详情可咨询名誉秘书A.R.布什比。 - I was assigned to Troop A of the 10th Cavalry.
我被派往第10骑兵队的A连。 - He brought me a large package.
他给我送来一个大包裹. - He missed the first prize by a whisker.
他和头奖擦肩而过.
词组短语
- a cappella 无伴奏合唱;阿卡贝拉;走在大街的女子;无伴奏
- A little 一点;一些;一点儿;一点点
- Bisphenol A 双酚A;双酚;酚甲烷;丙二酚
- 人马座A Sagittarius ;Centaurus;sgr
- FORM A 普惠制产地证;普惠制原产地证明书;普惠证;普惠制原产地证
短语
英英字典
- (NOT PARTICULAR) used before a noun to refer to a single thing or person that has not been mentioned before, especially when you are not referring to a particular thing or person
- (ONE) one
- You use a or an when you are referring to someone or something for the first time or when people may not know which particular person or thing you are talking about.
- You use a or an when you are referring to any person or thing of a particular type and do not want to be specific.
- You use a or an in front of an uncount noun when that noun follows an adjective, or when the noun is followed by words that describe it more fully.
- You use a or an in front of a mass noun when you want to refer to a single type or make of something.
- You use a in quantifiers such as a lot, a little, and a bit. (a lot), (a little), (a bit##bit)
- You use a or an to refer to someone or something as a typical member of a group, class, or type.
- You use a or an in front of the names of days, months, or festivals when you are referring to one particular instance of that day, month, or festival.
- You use a or an when you are saying what someone is or what job they have.
- You use a or an instead of the number "one," especially with words of measurement such as "hundred," "hour," and "metre," and with fractions such as "half," "quarter," and "third." (one)
- You use a or an in expressions such as eight hours a day to express a rate or ratio.
- &rarran informal or dialect word for have
- &rarr(usually linked to the preceding noun) an informal form of of
- acceleration
剑桥英英字典
柯林斯英英字典
专业释义
- 1a 级(城市或公司债券的等级,低于 2a 级,高于 3b 级)
- a 型血
- 腺嘌呤(adenine)的符号;丙氨酸(alanine)的符号
- 腺苷 (adenosine)
- 极光激酶A (aurora)
- 通风巷道,风道
- (原子)质量数(= mass number)
- 埃(angstrom),埃单位(angstrom unit)的符号;亥姆霍兹函数(helmholtz function)的符号
- 安 (ampere;amp)
- 安培 (ampere;amp)
- A磁碟机
- 丙胺酸 (alanine;ala)
- 丙氨酸 (alanine;ala)
- 钾霞橄黄长岩