p________：a system of fixed rules and formal behavior used at official meetings
举一反三
- We must follow a fixed system of notes used by others as a beginner of interpreting.
- Choose the correct expression to complete the sentence. _________ (乔姆斯基认为), language is an abstract system of rules which is used by human minds for transmitting and receiving ideas.
- However, in less formal meetings about ________ day-to-day business, people speak ________ to each other.
- A fixed factor is a factor of production that is used in fixed proportion to the level of output.
- Except on official __________ such as formal receptions, American society has a certain amount of informality.