the advent of new technology新技术的出现Swallows come by groups at the advent of spring.春天来临时燕子成群飞来.The advent of the Euro will redefine Europe.欧元的出现将重新定义欧洲....
使用牙刷去除牙垢很有帮助.The use of a toothbrush to keep tartar down is very helpful.除牙垢用带尖工具除去牙齿表面的 ( 污垢 )To remove ( tartar ) from tooth surfaces with a pointed instrument.我的牙齿上有许多牙垢.I have a lot of tartar on my teeth....