实词。
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
例子
a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron) used to specify wavelengths of electromagnetic radiation
any of several fat-soluble vitamins essential for normal vision prevents night blindness or inflammation or dryness of the eyes
one of the four nucleotides used in building DNA all four nucleotides have a common phosphate group and a sugar (ribose)
(biochemistry) purine base found in DNA and RNA pairs with thymine in DNA and with uracil in RNA
