Nowadays, more and more people are becoming aware of the danger situation threatening their environment and gaining consciousness about it . At last, we have started to take precautions for the world's natural source . Which are decreasing day by day . The most important step taken is re-using materials-in other words, recycling . It has become more importance that we reduce waste which pollutes the environment . Recycling paper has been the biggest succeed . Paper can be used six times over, then be burnt for the produce of energy . Plastic is the hardest material to recycle because there are very kinds which need to be treated difference . Metal is another material . The production of an aluminium can is more difficult than cycle it . Glass can be used again in a mix of asphalt and cement to pave streets . As a result. We should think for a while before we throw things away as they may still be use.