When engaged in conversation, ___________________.
举一反三
- When I came in the room, he was engaged _______ making the model airplane.
- When was the art exhibition according to the conversation?
- A young man joined the army when his country was engaged in World War I.
- When Men intend to start a conversation, they usually _________.
- 中国大学MOOC: When a country both exports and imports a type of commodity, the country is engaged in _______.