A:These days we can barely see any blue sky,can we?
B:No,we cannot,unfortunately.I remembered when I was little,it wasn't like this.
C:True.And my uncle told me that when he was young,he used to swim in the XXX river.But now,look at it,it's so dirty and polluted.I wouldn't wanna swim in it.
A:Really?In the XXX river,then there must be a lot of fish in it as well at that time.
C:I guess so.
B:Did you guys hear about the news about the Gaze in xxx( 填个你听到雾霾消息的城市名,我记不得是哪个城市了)
A:Yes,I did.It was so bad,wasn't it?
C:Yeah.Do you know what is the worst?If the water is polluted you can choose not to drink,but if the air is polluted,you cannot choose not to breath,you will die.
B:Exactly.That's remind me of London.
A:London?Why?
B:Don't you remember it was once called the"city of fog".
C:Yes,I know that.The old London fogs were the result of millions of coal fires producing particles (smoke) which encouraged the formation of fog on cold,still,winter nights.
B:True.The resulting mixture of smoke and fog was the classic "pea-souper" smog which gave London its reputation of being foggy.The Clean Air Acts of the 1950s eliminated the domestic coal fires which gave rise to the smogs.Nowadays,most people heat their homes with gas so it is very unlikely to see fog in London now.
A:Maybe we should also establish some laws to protect our enviroment,so that these kind of things won't happen again.
C:You are right.We can also protect the enviroment from small actions,such as recylcing and reusing.