0 a written message from one person to another, usually put in an envelope and sent by post -- 信,信件
1 any of the set of symbols used to write a language, representing a sound in the language -- 字母
the letter D 字母D
2 used to refer to a standard size of paper in the US, 8.5 inches by 11 inches -- (美国)标准信纸(长11英寸,宽8.5英寸)
I had a lovely, long, chatty letter from my friend this morning.
What letter does it start with?
How many letters are there in the alphabet?
Z is the last letter of the alphabet.