详细解释:一...就
词意辨析：
once, as soon as两者均为从属连词，引导时间状语从句，都表示主句的动作紧跟在从句的动作之后发生。
once: 除表时间外，还表示条件，一般译作“一旦......就......”。once he makes up his mind，he’ll never give it up.
他一旦下定决心，就决不会放弃（本句不可用as soon as）。
as soon as: 强调的只是时间，译作“刚......就......”或“一......就......”。as soon as i get to beijing，i’ll write to you.
我一到北京就写信给你。例句：
I'll write you as soon as I get there.我一到那儿，就给你写信。