who-are-you signal

例句：

1. 1. The policemen used their flashlights as signals to guide the way.
   警察使用手电筒作为信号来引导道路。
2. 2. The new policy is a clear signal of the government's intentions.
   新政策是政府意图的明确信号。
3. 3. The sudden drop in stock prices was a strong signal that the economy was facing problems.
   股票价格的突然下跌是一个强烈的信号，表明经济正面临问题。