释义
n. 符号,正负号,手势,迹象,招牌 v. 签，做手势，做标记
例句
1. Dark clouds are a sign of rain or snow. 乌云是雨或雪将至的预兆。 2. The football team has signed two new players. 该足球队已签约聘用了两名新队员。