something or someone that acts as an early and less advanced model for what will appear in the future, or a warning or sign of what is to follow

Germany's Green party was said to be the forerunner of environmental parties throughout Europe. 德国绿党据说是全欧洲环保政党的先驱。

The drop in share prices in March was a forerunner of the financial crash that followed in June. 3月份股价的下跌是随后6月份金融崩溃的一个预兆。