Authorities here depend on the public to keep an eye out for unusual packages or passengers.

VOA: standard.2010.04.01

Keep an eye out for this, particularly in pop music.

注意一下音乐的结构,特别是流行音乐

耶鲁公开课 - 聆听音乐课程节选

Keep an eye out for this, particularly in pop music.

注意一下音乐的结构,特别是流行音乐

耶鲁公开课 - 聆听音乐课程节选