a
英 [ə; eɪ]
美[e]
- 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）
英英释意
- 1. the blood group whose red cells carry the A antigen
- 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