1)名词短语引导时间状语，如the moment, the minute, the instant, the day, the year
She wired her father the moment she reached the hotel.
The instant she saw me she knew I was his brother.
I will notify them of your arrival the minute you reach the city.
这里the moment, the minute, the instant都相当于... as soon as，二
2)某些由副词充当的连词如immediately, directly, instantly也可引导时间状语，愈
为二、. as soon as...。例如:
I got in touch with him immediately I received his letter.
The doctors performed an operation on the patient directly he was sent to the hospi-
I recognized her instantly I saw her get down the train.
On inquiring，we found that the plane had already left.
On entering the room，I saw him seated at the corner.
Upon his arrival，all the audience stood up and applauded.
4) when, while, whenever可以引导无动词时间状语从句.例如:
Experience，when dearly bought，is seldom thrown away.
We read them when young; we remember them when old.
Whenever in difficulty，you can count on our support.
Do not leave the building until instructed to do so.
Once printed，this book will be very popular.