letter基本解释
n,信；[语]字母，文字；证书；文学，学问；字面意义,同近
letter相关例句和用法There are 26 letters in the English alphabet..英语字母表有26个字母。
letter英英释义信；字母，文字；证书；文学，学问；字面意义英释中释na written or printed message that is usually put in an envelope and sent by mail
letter短语letter of credit,n. [商]（银行发行的）信用证.短语
