In the 13th century, the Italian traveler, Marco polo , traveled a long way to China , During his stay in China , he saw many wonderful things . One of the things he discovered was that the Chinese used paper money . In western countries , people did not use paper money until the 15th century . However , people in China began to use paper money in the 7th century . A Chinese man called CaiLun invented paper almost 2000 years ago. He made it from wood . He took the wood from trees and made it into paper . He then put these pieces of paper together and made them into a book . Now paper still comes from trees . We use a lot of paper every day ! If we keep on wasting so much paper , there will not be any trees on the earth . If there are no trees , there will be no paper . Every day , people throw away about 2800 tons   of paper in our city . It takes 17 trees to make one ton of paper . This means that we are cutting nearly 48000 trees every day . Since it takes more than 10 years for a tree to grow , we must start using less paper now . If we don't , we will not have enough time to grow more trees to take the place of those we use for paper . So how can we save paper ? We can use both sides of every piece of paper , especially when we are making notes .We can choose drinks in bottles instead of those in paper packets . We can also use cotton handkerchiefs   and not paper ones . When we go shopping , we can use fewer paper bags . If the shop assistant does give us a paper bag, we can save it and reuse it later . Everyone can help to save paper . If we all think carefully , we can help protect trees . But we should do it now , before it is too late . Which of the following is NOT the way of saving paper ?
To use both sides of every piece of paper To use the paper bags from shops more than once To use cotton handkerchiefs instead of paper ones To grow more trees