定义
a radar: 雷达装置
- "Something big has just appeared on the radar!"
- "The first mate has spotted a blip on the radar three knots ahead."
- "The hot air balloon was being tracked by satellite and radio until 7:32, at which time it disappeared from the radar, and the radio signal was replaced by static."
- "Air Traffic Controller : I'm unable to identify you on radar."
- "I want you to make a series of 90-degree turns so that I can identify you on radar."
