重点讲解：
1. walk up to
走近，走向；
eg. She walk up to the desk and ask to see the manager.
她走到办公桌前要求见经理。
eg. He walked up to me and asked me where the post office was.
他走到我面前，问邮局在哪儿。
2. turn on
打开（设备）；接通
eg. I want to turn on the television.
我想开电视。
eg. She asked them why they hadn't turned the lights on.
她问他们为什么不开灯。