[] () the sound used to signal when business starts and ends at a stock exchange证券交易所开盘和收盘时的铃声◆Stocks (= their prices) are expected to drop after the opening bell on Wall Street.华尔街开盘铃声响起后的股票价格预料会下跌。●aˈlarm/ˈwarning bellsused in expressions to mean that people are starting to feel worried and suspicious about sth警号◆The publisher set alarm bells ringing when it warned that its profits had fallen dramatically.利润大幅度下降时，出版商就会开始有所忧虑。