a
n. 字母A；第一流的；学业成绩达最高标准的评价符号
abbr. [物]安（ampere）
art.
一（个）；每一（个）；任一（个）；
英英释义
a[ ei ]
n.
a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
同义词：angstromangstrom unit
any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
同义词：vitamin Aantiophthalmic factoraxerophthol
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
同义词：deoxyadenosine monophosphate
(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
同义词：adenine
the basic unit of electric current adopted under the Systeme International d'Unites
"a typical household circuit carries 15 to 50 amps"
同义词：ampereamp
the 1st letter of the Roman alphabet
同义词：letter a
the blood group whose red cells carry the A antigen
同义词：type Agroup A
双语例句
用作冠词(art.)
There is a pen on the table.
桌子上有一支笔。
We have a problem.
我们有个问题。
I can only carry two at a time.
我一次只能带两个。
Let's go to a Chinese restaurant.
我们去一家中餐餐馆。
A cat is an animal.
猫是动物。
权威例句
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Marching cubes: a high resolution 3D surface construction algorithm
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A Gene-Expression Signature as a Predictor of Survival in Breast Cancer — NEJM
MOLMOL: a program for display and analysis of macromolecular structures.
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A decision-theoretic generalization of on-line learning and an application to boosting
Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic ...
a
a: [OE] The indefinite article in English is ultimately identical with the word one (as is the case, even more obviously, in other European languages – French un, German ein, and so on). The ancestor of both a(n) and one was ān, with a long vowel, but in the Old English period it was chiefly used for the numeral; where we would use a(n), the Anglo-Saxons tended not to use an article at all. Ān begins to emerge as the indefinite article in the middle of the 12th century, and it was not long before, in that relatively unemphatic linguistic environment, its vowel became weakened and shortened, giving an.And at about the same time the distinction between an and a began to develop, although this was a slow process; until 1300 an was still often used before consonants, and right up to 1600 and beyond it was common before all words beginning with h, such as house.=> one
a (1)
indefinite article, mid-12c., a variation of Old English an (see an) in which the -n- began to disappear before consonants, a process mostly complete by mid-14c. The -n- also was retained before words beginning with a sounded -h- until c. 1600; it still is retained by many writers before unaccented syllables in h- or (e)u-, but is now no longer normally spoken as such. The -n- also lingered (especially in southern England dialect) before -w- and -y- through 15c.
a (2)
as in twice a day, etc., from Old English an "on," in this case "on each." The sense was extended from time to measure, price, place, etc. The habit of tacking a onto a gerund (as in a-hunting we will go) died out 18c.
1. She spread a sheet on the sofa for me.
她为我在沙发上铺了一条单子。
《21世纪大英汉词典》
2. She buddied up with a student from another university.
她与来自另一大学的一名学生交朋友。
《21世纪大英汉词典》
3. They presented a sum of money to the college in memory of their son.
他们向学院赠送了一笔款项以纪念他们的儿子。
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4. It is a luxury to me.
它对我来说是一种奢侈。
《新英汉大辞典》
5. We all saw a ship weather on us that day.
那天我们都看到一条船在我们上风行驶。
《21世纪大英汉词典》
6. He looks like a soldier.
他看上去像一个军人。
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7. Why not have a try?
为什么不试一试?
《新英汉大辞典》
8. No one could phony a list like that.
没有人能够假造像这样的一份清单。
《21世纪大英汉词典》
9. As a scholar, he is far above me.
他作为一名学者，比我高明得多。
《21世纪大英汉词典》
10. If you can use a word correctly and effectively, you comprehend it.
你如果能正确和有效地使用一个字，你就了解它了。
《新英汉大辞典》
11. Who tell you I hang about with a gang?
谁告诉你我和一帮坏孩子在鬼混?
《21世纪大英汉词典》
12. I think you can weave a story around this incident.
我想你可以围绕这一事件编一个故事。
《21世纪大英汉词典》
13. He offered me a bed.
他提供我一个床位。
《新英汉大辞典》
14. As a scientist,he disbelieves in Jesus.
作为一名科学家，他不信耶稣。
《21世纪大英汉词典》
15. He jotted down a note for her and then left.
他匆匆为她写下了一个条子然后离开了。
《21世纪大英汉词典》
16. He lived in a flat above the shop.
他住在那商店上面的一套房间里。
《21世纪大英汉词典》
17. I do not think much of her as a musician.
她作为一名音乐家，我认为不怎么样。
《21世纪大英汉词典》
18. She teaches in a state university.
她在一所州立大学任教。
《21世纪大英汉词典》
19. He uttered a cry of pain.
他发出一声疼痛的叫喊。
《21世纪大英汉词典》
20. He floored his opponent with a fine punch in the first round.
他在第一轮比赛中猛击一拳就把对手打倒在地。
《21世纪大英汉词典》
21. Someone came out with a most useful suggestion.
有人提出了一个非常有益的建议。
《21世纪大英汉词典》
22. This money will carry us for a month.
这笔钱将维持我们一个月的生活。
《21世纪大英汉词典》
23. The novel portrays the growth of a fighter.
这本小说描写了一个战士的成长。
《新英汉大辞典》
24. A book is not judged only on its length.
不能只根据篇幅长短来评价一本书。
《新英汉大辞典》
25. Then he hailed a taxi for her.
然后他给她叫了一辆出租车。
《21世纪大英汉词典》
26. I will not breathe a word of your secret to another man.
关于你的秘密，我决不会向别人泄露一个字的。
《21世纪大英汉词典》
27. He led us to a room upstairs.
他把我们带到楼上一个房间里。
《新英汉大辞典》
28. My pen turned up in a drawer.
我的钢笔在一个抽屉里找到了。
《21世纪大英汉词典》
29. My pen turned up in a drawer.
我的钢笔在一个抽屉里找到了。
《21世纪大英汉词典》
a
