I do not become aware of the danger until he warn me 直到他给我警告我才觉察到危险。
2.
She was / became aware of the danger 她(终于)觉察到危险。
3.
Passive smoking has been under attack in recent years as more nonsmokers are becoming aware of the dangers of breathing second - hand tobacco smoke 更多的不吸烟者开始意识到吸进他人吐出烟雾的危险,近年来人们一直在声讨被动吸烟。