参考答案：
Communication Instruments
Communication instruments have been playing an important role in the busy world of today. Of them all, three kinds are most commonly used.
First, the most widely-used and the most conventional one is mail, by which people use written words to exchange information. Although it is not so fast as other types, mail is the cheapest means of communication to convey ideas and thoughts, in every detail. Then comes a telephone, which enables people to communicate conveniently without restrictions of time and place. With the development of modem science and technology, computers have become a more recent kind of communication instrument. Communication with computers is fast and easy. E-mail is the best instance.
Owing to their peculiarities, these three sorts of communication instruments have won millions of people respectively. They help to bring people all over the world closer.