7. An English letter always requires ________, whether it is formal or informal.
举一反三
- An invitation card is always used on informal occasions while an invitation letter is always used on formal ones.
- Sending reminders or not depends on whether the invitation is formal or informal.
- According to the occasion, the invitation letter is divided into two types: formal and informal.
- An invitation letter is a kind of social letter,it is divided into formal invitation and informal invitation.( )
- In what situation is the invitation letter often used A: Formal situations B: Informal situations C: Both formal and informal situations