Letters of congratulations are usually lengthy.
举一反三
- I hope my boyfriend writes lengthy letters to show his love for me, but his letters are always so _____ .
- Informal letters are usually business letters or written to strangers.（ ）
- letters are usually delivered by a postman whereas e-mails are sent through
- The seat number of your flight is usually a combination of letters and numbers.
- In full-blocked business letters, all text of the letter is written from , and usually there is a between paragraphs.