a是什么意思
网络释义：一个；一种；一；一位
1 . Liver and kidney are particularly rich in vitamin A .
肝脏和肾脏富含维生素A。
2 . Details are available from the Hon. Sec. A .R. Bushby.
详情可咨询名誉秘书A.R.布什比。
3 . I was assigned to Troop A of the 10th Cavalry.
我被派往第10骑兵队的A连。
4 . Passes are graded from "A " down to "E".
及格分为A到E几等。
5 . Use only clean, Grade A, perfect eggs.
只用表面干净、无磕碰的A级鸡蛋。
2.a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
3.any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
4.one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
5.(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
6.the basic unit of electric current adopted under the Systeme International d'Unites;
a typical household circuit carries 15 to 50 amps
7.the 1st letter of the Roman alphabet
1.①atto阿〔托〕：10－18
2.②arterial blood动脉血(用作下角标)
3. ①specific absorptivity比吸收率
4.②activity (thermodynamic activity of a chemical species)〔化学物质热力〕效能
5.③acceleration加速，加速度
6. 〔前缀〕意为①缺乏，缺少，无：在元音或h前，则用an
7.②分离，分隔
8.离开，远离
1.抵押数
2. 担保数
1.宣布股利以后当年额外的现金股利
2.I knew enough about him that I had him over a barrel.
我对他的底细一清二铯，所以我能把他完全控制在手中。
3.l know they are on a hiding to nothing.
我知道他们丝毫没有获胜的希望。
4.She has a crush on the new gym mistress.
她非常喜欢新来的女体育老师。