5. 时间状语从句：as的用法
1)某事一发生，另一事立即发生
As the sun rose the frog dispersed. 太阳一出来雾就消散。
They strolled into the garden as the music ceased. 音乐声一停，他们就走进花园。
2)在某事发生的过程中另一事发生
I heard the murmur of their voices as I crossed the hall. 我走过大厅的时候听到他们在嘀咕什么。（两个动作都是一般时态）
Just as he was speaking there was a loud explosion. 正当他在说话的时候，一声巨响。
（从句用进行时态）
3)两个动作同时发生
He smiled as he passed. 他路过的时候笑了一下。（两个都是短暂动作）
As she sang, the tears ran down her cheeks. 她一边唱歌，眼泪一边从脸颊淌下。
Helen heard the story as she washed. 海伦一边洗衣服一边听故事。
He saw that she was smiling as she read.
他看到她一边看着书一边笑。（两个都是延续性动作）
We get wiser as we get older.
我们随着年龄的增长而变得聪明起来。（随着时间的变化而变化）
6. 时间状语从句：when的用法
以when引导的时间状语从句中，既可用短暂性动作也可用延续性动作。
I bought the car when I received my first salary.（短暂性动作）我是在领第一笔薪水的时候买的车。
Don't get excited when you talk.（延续性动作）说话的时候不要激动。
