a
音標發(fā)音
- 英式音標 [?; e?]
- 美式音標 [?; e]
- 英式發(fā)音
- 美式發(fā)音
基本解釋
- art.一(個)；每一(個)；任一(個)
- n.英語字母表的第一個字母；學業(yè)成績得優(yōu)者；表示“最好”的符號
用法辨析
- 通常來說，a 是用在以輔音開首的詞前面，an 是用在以元音開首的詞前面；
- 可數名詞前面用 a（或 an），不可數名詞前面不可用a（或 an)，如可以說 a healthy boy，卻不可以說 a health；
- 在特定情況下，a（或 an）可以用在復數形式前面:習語中有a few (books)，a great many (books)等表示方法。在表示時間或款項的短語前面，如 a further five minutes。在若干在形式上是復數而在意思上是單數的單詞前面，如 a barracks，a links。在美國口語中，如 a good ways，a long ways；
- a（或 an）有時有“一個而不是那所要的一個”的意思。a 也有“任何一個”的意思。I got a letter indeed，but it was from a friend. 事實上，我收到了一封信，但只是一個朋友的來信。I wanted to read a book，I did not care whether it was a history，a novel，or a biography.
- a 與 few 搭配使用時，few 是“很少”，有“幾乎沒有”的意思。a few 是“若干”，有“頗有幾個”的意思。注意，only a few 卻等于 few，也是“很少”的意思。
英漢例句
- Liver and kidney are particularly rich in vitamin A.
肝臟和腎臟富含維生素A。 - Details are available from the Hon. Sec. A.R. Bushby.
詳情可咨詢名譽秘書A.R.布什比。 - I was assigned to Troop A of the 10th Cavalry.
我被派往第10騎兵隊的A連。 - He brought me a large package.
他給我送來一個大包裹. - He missed the first prize by a whisker.
他和頭獎擦肩而過.
詞組短語
- a cappella 無伴奏合唱;阿卡貝拉;走在大街的女子;無伴奏
- A little 一點;一些;一點兒;一點點
- Bisphenol A 雙酚A;雙酚;酚甲烷;丙二酚
- 人馬座A Sagittarius ;Centaurus;sgr
- FORM A 普惠制產地證;普惠制原產地證明書;普惠證;普惠制原產地證
短語
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
劍橋英英字典
柯林斯英英字典
專業(yè)釋義
- 1a 級(城市或公司債券的等級，低于 2a 級，高于 3b 級)
- a 型血
- 腺嘌呤(adenine)的符號；丙氨酸(alanine)的符號
- 腺苷 (adenosine)
- 極光激酶A (aurora)
- 通風巷道,風道
- (原子)質量數(= mass number)
- 埃(angstrom),埃單位(angstrom unit)的符號;亥姆霍茲函數(helmholtz function)的符號
- 安 (ampere;amp)
- 安培 (ampere;amp)
- A磁碟機
- 丙胺酸 (alanine;ala)
- 丙氨酸 (alanine;ala)
- 鉀霞橄黃長巖