alert

campaigns to alert the public to the dangers of HIV.让公众意识到艾滋病病毒危险的宣传活动

Taking notes is one of the best ways to stay alert in lectures..记笔记是听课时集中注意力的最佳方法之一。

Red Alert (红色警戒) 是风靡全球的电脑游戏记忆

alert someone to sth使...警觉；使...警惕

on the alert提防；警戒著；随时准备著

red alert紧急警报，红色警报；应急状况

真题例句...if the left hemisphere was staying alert to keep guard in a strange environment...CET42017.12阅读理解

真题例句...but instead will alert their friends...CET42008.12阅读理解