搜索
a
01
一个, 一
used when we want to talk about a person or thing for the first time or when other people may not know who or what they are
1.1
一个
used before a noun when we are not talking about a specific person or thing
02
一个, 一
used to show someone or something belongs to a group or type
A
01
A, 一个
the musical pitch A, which is a specific note in the diatonic scale commonly used in Western music
What is "A"?
In music, the pitch "A" is a specific note that is used as a reference point for tuning and playing. It is one of the twelve notes in the musical scale and is represented by the letter "A". Each "A" note can be higher or lower in pitch depending on the octave. For example, "A4" is a common reference pitch that vibrates at 440 Hertz and is often used to tune musical instruments. This note helps musicians keep their music in tune and create harmonious sounds.
02
一埃, 一种测量单位埃
a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
03
A型, A型血
the blood group whose red cells carry the A antigen
04
a
the 1st letter of the Roman alphabet
05
一个核苷酸, 核苷酸的单位
one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
06
腺苷
(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
a
det
例子
She found a job at a company downtown.
She bought a new book yesterday.
There is a movie theater in the mall.
She found a job at a company downtown.
They were excited to see a shooting star in the sky.
