中国大学MOOC: The formal letter without signature is valid.
举一反三
- The formal letter without signature is valid.
- 中国大学MOOC: A letter of invitation can be classified into formal invitation and informal invitation.
- 中国大学MOOC: An effective application letter is quite different from a formal business letter.
- 中国大学MOOC: A progress report can take the following forms: letter, __________, email, or formal report.
- 中国大学MOOC: In a formal business letter, we should always try to state our purpose at the beginning.