很多呢. be about to do when 当正要做什么的时候怎么样了 e.g.I was about to leave the room when he came in.我正要离开房间时他进来了. be doing when 当正在做什么的时候怎么样了 e.g.She was thinking of her friend when Tom called her.她正在想她朋友的时候Tom叫了她一声. had done when 刚做完什么的时候怎么样了 e.g.I had just walked out of the kitchen when someone knocked at the door.我刚从厨房出来就有人敲门. while 当（注：一般后接doing或表状态的词语） e.g.1 He was singing while walking.他边走边唱. e.g.2 Jane left her study while the laptop was still on.Jane的笔记本还开着她就离开了书房. 其他的还有吧……
Crystallam88
