实战口语情景对话 第1227期:How much sleep do you usually get? 你一般睡几个小时?

重点讲解：
1. used to do sth. 过去常常；过去曾；
例句：They used to take off their clothes and go skinny dipping in the creek.
他们以前常常脱了衣服在小河里裸泳。
2. go on 进行；发生；
例句：She was oblivious to what was going on around her.
她没有注意周围发生的事。
3. be bad for 不利的；有害的；
例句：Caffeine is bad for your health.
咖啡因对人体健康有害。
4. go back to 回到（过去）；
例句：The best way to keep babies off sugar is to go back to the natural diet and eat lots of fresh fruit.
避免婴儿摄入食糖的最好办法是让其回归自然的饮食，多吃新鲜水果。