It often seems that everyone in Britain has a mobile phone. We use them as alarm clocks, c

alculators, to help with exam revision, to pay city congestion charges, to send photos of ourselves on holiday with our new 3G phone--and even to talk with other people. And that's where the problems can start.

Firstly when do you use them？ The etiquette of using mobiles is changing. Originally people turned away when speaking with someone. Now they'll just talk about anything from work to romance to when they'll be home--at the top of their voices--without anyone minding. Or not minding much. Or--OK being too polite to say they can't stand the fact that person sitting next to them on the train is talking about last night's party while they're trying to read the paper.

Secondly, when do you not use them？ In Britain, the answer to that is simple. You don't use a mobile phone---except with a fixed hands free set--while you're driving. A new law came into force at the end of 2003. Anyone caught using a hand--held mobile while driving risks a fixed penalty of ￡30 or a fine of up to ￡1,000 if convicted plus three points on their licence.

However, not everyone takes note of the law and the police have been prosecuting drivers for breaking it. The worst offenders are people living in South West Scotland. BBC transport correspondent Tom Symonds says that over 800 have been caught in Strathclyde compared to just 17 in Suffolk. (It's not clear whether that means that Scots have more friends or are just worse drivers!)

Finally, do try not to lose your mobile. It's not the phone itself which matters--it's easy enough to replace a handset. But your SIM card is another matter. It has all your contacts stored on it. And without your contacts list--well, who could you phone？

The passage mainly discusses ______.

A．the advantages and disadvantages of using the mobile phone

B．the manners of using the mobile phone

C．the problems brought by the mobile phone

D．the development of the mobile phone industry