Read the following passage and choose the best answer (A, B, C, D):
Books have been around for thousands of years. When ancient civilizations first started developing writing systems, they would write on just about anything, from stone to tree bark. Ancient Egyptians were the first to use paper-like materials, called “papyrus”, which they made by pounding flat the woven stems of the papyrus plant. It was not long before the ancient Egyptians began gluing together papyrus sheets to form scrolls, which were the first steps toward books as you know. The birthplace of bookbinding is considered to be India in the 2nd century B.C., where Hindi scribes would bind palm leaves that were etched with religious texts between two wooden boards using twine. The technique became popular in the Middle East and Eastern Asia, and spread to the Romans by the 2nd century A.D. In the mid-15th century, German Johannes Gutenberg invented the first mechanical printing press. His invention was revolutionary because it enabled mass production of booksfor the first time. Before the printing press, a few pages per day could be produced by handcopying. Afterward, printing presses could produce as many as 3,600 pages per day. Today, modern publishers take advantage of incredible advances in technology to produce books in many sizes and shapes very quickly. Although there are many types of processes and machines available, most processes involve similar steps. Printers print the text of a book on large sheets of paper, sometimes as large as a newspaper page. Working with large volumes of paper allows printers to lower costs and produce books more efficiently.The large sheets are then cut into smaller pages that are still about twice the size of a finished book. The smaller pages are then divided into small groups, folded in half, and sewn together. Lastly, the folded and sewn pages are cut down to their finished size and glued to the spine of the final book’s cover. Depending on the quality of the book, additional finishing touches may be added, such as blank pages at the front and back of the book or special tape around the edges of the cover to increase durability. Although printed books may never go away completely, today’s readers will most certainly soon become more familiar with e-books. “E-book” refers to an electronic book, which is simply the text of a book displayed electronically, either via the Internet, a CD-ROM, a tablet, an e-book reader, or even a mobile phone. As electronic devices, such as tablets and mobile phones, become more commonplace, e-books are expected to become more and more popular. One of the benefits of e-books is that they save paper, which helps the environment by reducing the demand for trees
5. According to paragraph 4, how to produce books more cheaply and efficiently?