attention signal

例句：

1. 1. The teacher gave the student anattention signal to indicate that he needed topay attention.
   老师给那个学生一个注意力信号，让他需要集中注意力。
2. 2. The researcher noticed a sudden change in the animal's behavior and gave an attention signalto alert others.
   研究员注意到动物行为突然改变，并发出了注意力信号来警告其他人。
3. 3. The doctor used a light beam asan attention signal to guide the patient tothe operating room.
   医生使用一束光作为注意力信号来引导病人前往手术室。