很多呢.
be about to do when 當(dāng)正要做什么的時候怎么樣了
e.g.I was about to leave the room when he came in.我正要離開房間時他進(jìn)來了.
be doing when 當(dāng)正在做什么的時候怎么樣了
e.g.She was thinking of her friend when Tom called her.她正在想她朋友的時候Tom叫了她一聲.
had done when 剛做完什么的時候怎么樣了
e.g.I had just walked out of the kitchen when someone knocked at the door.我剛從廚房出來就有人敲門.
while 當(dāng)（注：一般后接doing或表狀態(tài)的詞語）
e.g.1 He was singing while walking.他邊走邊唱.
e.g.2 Jane left her study while the laptop was still on.Jane的筆記本還開著她就離開了書房.
其他的還有吧……