释义
n. 大头钉,行动方针 v. 以大头针钉住,附加,跟随
例句
1. My mother tacked the sleeves on before sewing them. 我妈妈在把袖子缝好之前，先用大针脚把它缝好。 2. The speaker suddenly changed tack and left us all rather confused. 演讲人突然改变了论调，把我们都搞糊涂了。