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 are a 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.