A: Hello, John! What were you doing at chemistry class earlier？ You didn't look at the teacher the whole time!
B: I have something cool. Look, this is my new 3G mobile phone. I just cannot stop playing with it!
A: What is a 3G mobile phone？
B: It is so popular now, I cannot believe you haven't heard of it. With 3G mobile phones, you can send text message, make video calls and watch mobile TV.
A: Wow, cool! Show me how to watch mobile TV. It's NBA time!
B: Sure. You just need to press one button and choose the channel you want to watch. It is quite easy.
A: No wonder it is so popular with college students. I should get one.
对话解析：
1. A询问B在化学课上的行为，B提到自己在看新买的3G手机。
2. A好奇3G手机是什么，B解释了3G手机的功能，包括发送短信、视频通话和观看移动电视。
3. A对观看移动电视感兴趣，B演示了如何操作。
4. A认为3G手机在大学里很流行，表示自己也想买一个。
这个对话展示了两个朋友在谈论科技产品时的兴奋和兴趣，同时也反映了3G手机在当代社会中的普及程度。
