Jerry: OK, so what do you think is the most useful invention then?

Sandra: What, in the world? Yeah, well, that's a difficult question! Hmm, I'm pretty sure I couldn't live without a television!

Jerry: Really?

Sandra: Yes, really! I mean, what would I do after school every day and at the weekends?

Jerry: But television is just entertainment, isn't it? Do you think it's useful?

Sandra: Well, yeah - it means we can learn about major news events. You know, with digital television and 24-hour channels, we can always find out what's happening in the world. Yeah, I think it's really useful. But anyway, what about you then? What invention do you think is the most useful?

Jerry: Hmm ... well, my computer means everything to me.

Sandra: Do you use it a lot?

Jerry: Yes, all the time. Yes, I'd certainly say it's the most useful invention in our house – even more useful than my mobile phone! You know, I do my homework on it, send emails to my friends, and visit websites and chat rooms.

Sandra: Do you have it in your bedroom?

Jerry: Well, no, it's in the study. You see, my mum and dad sometimes use it for work, too. And hey, if it crashes, we all get really annoyed!

Sandra: We haven't got a computer at home, so I don't use one much.

Jerry: Really, I can't imagine life without a computer!

What does Sandra think is the most useful invention?