out of the blue:unexpectedly; without warning 出乎意料;突然;晴天霹雳
His resignation came right out of the blue.
他的辞职来得很突然.
Go ahead:尽管说,做
Linger in one's mind:萦绕在脑际
come across somebody/something: to meet or find somebody/something by chance (偶然)遇见,碰见,发现
I came across children sleeping under bridges.
我偶然发现睡在桥下的孩子.
She came across some old photographs in a drawer.
她在抽屉里偶然发现了一些旧照片.