A
A暫存器(同register,arithmetic)
A
n 1: the blood group whose red cells carry the A antigen [syn: type
A, group A]
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 [syn: angstrom, angstrom unit]
3: any of several fat-soluble vitamins essential for normal
vision; prevents night blindness or inflammation or
dryness of the eyes [syn: vitamin A, antiophthalmic
factor, axerophthol]
4: one of the four nucleotides used in building DNA; all four
nucleotides have a common phosphate group and a sugar
(ribose) [syn: deoxyadenosine monophosphate]
5: (biochemistry) purine base found in DNA and RNA; pairs with
thymine in DNA and with uracil in RNA [syn: adenine]
6: the basic unit of electric current adopted under the Systeme
International d'Unites; "a typical household circuit
carries 15 to 50 amps" [syn: ampere, amp]
7: the 1st letter of the Roman alphabet
A
Alpha, the first letter of the Greek alphabet, as Omega is the
last. These letters occur in the text of Rev. 1:8,11; 21:6;
22:13, and are represented by "Alpha" and "Omega" respectively
(omitted in R.V., 1:11). They mean "the first and last." (Comp.
Heb. 12:2; Isa. 41:4; 44:6; Rev. 1:11,17; 2:8.) In the symbols
of the early Christian Church these two letters are frequently
combined with the cross or with Christ's monogram to denote his
divinity.