from this cartoon, we can see that at the top end of the river,is a chemical factory and a paperrnaking factory which send out and poisonous wastes. and the river has been seriously polluted,n be seen from the color of it. along this "black" river, there area few people selling fresh water which must have been taken from far away places.

　　at the first glance, it is very strange to us how can people sell water along the river, but this is the case, because the water in this river is undrinkable. this presents a serious social problem--environmental pollution. with the development of economy, our living standards have been greatly improved. but we can＇ t ignore the fact the air we take in and the water we drink today are not as fresh and clean as they used to be. some kinds of pollution can even be deadly to people. it is high time that we took some measures to solve the problem.

　　i think we can first call people＇s attention to this problem so that they will be aware of the serious consequences of it. then,we can pass certain laws to restrain the factories from sending out wastes. finally, we can do more resarch work to find out ways to deal with the wastes.

　　keep square clean, tidy on sunday, still on display on tian＇anmen square were dozens of floats that were paraded along chang＇ an avenue during the nationalday celebrations. thousands of people strolled on the narrow lanes be- tween the floats that fragmented the square, busily taking photos. not far from the noisy crowds, yellow leaves fell nonchalantly from locust trees along the driveway, sending out the first signals of the coming autumn. but even if all the leaves fall, they still cannot cover the brown and black spots on the hitish stones in the huge square.

　　such stains of chewing gum, stale oil or some worse blemish have remained a constant pain for city cleaners since the square ＇was re-opened a few months ago after renovations to celebrate the 50th anniversary of the founding of the people＇s republic of china.

　　few renovation project planners likely foresee this discouraging outcome. originally, they merely intended to give the city a facelift. the square was indeed impeccable when new: the-white terrazzo surface not only looks clean but it was made with materials that help prevent it from becoming slippery.

　　however, as time goes by, the virtue becomes the vice: the surface attracts and accentuates dirt. as a result, china＇ s most high profile site has to suffer the indignity of being paraded daily efore thepublic in a humiliation state.

　　while the tourists who litter should bear the bulk of the blame, the renovation designers should also have learned something: including the square＇s sanitary maintenance issue into their consideration.