People use the word "unidentified" to describe the reported flying objects .because what these objects are is still unknown.
举一反三
- What is an UFO? A: It is an Unknown Flying Object. B: It is an Unidentified Flying Object. C: It is an Unknown Flowing Object. D: It is an Unidentified Flowing Object.
- When connected to the Internet of Things, what can the objects people use every day do?
- 中国大学MOOC: In the USA in 1967, a man reported ________ UFO (unidentified flying object).
- In the USA in 1967, a man reported ________ UFO (unidentified flying object). A: X B: a C: an D: the
- They developed objects for astronauts to use in______space.