A
1.N-VAR 可变名词英语字母表的第1个字母 A is the first letter of the English alphabet.
2.N-VAR 可变名词C大调音阶中的第六音；A音 In music, A is the sixth note in the scale of C major.
3.N-VAR 可变名词（作业、考试等）甲等，优等 If you get an A as a mark for a piece of work or in an exam, your work is extremely good.
4.（用于首字母为 a 的一些单词的缩写，如 acceleration，ampère和answer） A or a is used as an abbreviation for words beginning with a, such as 'acceleration', 'ampère', or 'answer'.
5.PHRASE 短语从一处到另一处；从甲地到乙地 People talk about getting from A to B when they are referring generally to journeys they need to make, without saying where the journeys will take them.
【搭配模式】：PHR after v
Cars are for getting people from A to B in maximum safety.
汽车用于将人们尽可能安全地从一地送往另一地。
