when,as soon as,no sooner…than,hardly…when,
1、as soon as…
例句：I came as soon as I heard the news. 我一听到消息马上就来了。
2、No sooner…than…
例句：No sooner had he sat down than it began to rain. 他刚坐下，天就开始下雨啦。
3、Hardly…when…
例句：Hardly had he finished when someone rose to refute his views. 他刚一说完，就有人起来驳斥他的观点。
4、Scarcely…when…
例句：Scarcely had I opened the door when the dog came running in. 我一开门，那条狗就跑了进来。
5、Immediately…
例句：She would help her parents do the housework immediately she got home. 她一回到家就帮助父母做家务。
6、the moment (that) sb. does/says sth.
例句：He said he would phone you the moment he got home. 他说他一到家就给你打电话。
7、the minute…
The policeman rushed to the spot the minute he heard of the road accident. 那名警察一听到车祸发生，就急忙赶到现场。
8、the instant…
例句：The driver pulled on the brake the instant he saw two kids jumping up and down on the road. 一看见在马路上蹦来跳去的两个孩子，司机就立即踩了刹车。
9、once…
例句：Once she arrives， we can start. 她一到，我们就可以开始。
10、On/Upon (doing) sth.
例句：On hearing the news of the air attack most foreigners headed for the border. 一听到空袭的消息，大多数外国人便前往边境。
