常用引导词：when, as, while, as soon as, while, before, after, since , till, until
特殊引导词：the minute, the moment, the second, every time, the day，the instant,         immediately, directly, no sooner … than, hardly …when, scarcely … when
I didn’t realize how special my mother was until I became an adult.
While John was watching TV, his wife was cooking.
The children ran away from the orchard(果园) the moment they saw the guard.
                No sooner had I arrived home than it began to rain.
                Every time I listen to your advice, I get into trouble.