Câu hỏi:

Read the following passage and choose a word to fill in each gap

Before the telephone invented by Alexander Graham Bell in 1876, it was hard for people (31)……over long distances. They wrote letters to each other. It could take days or even weeks for letters to be (32)……Then people learned how (33)……telegraph messages. The messages traveled as electric signals that represented a code of dots and dashes. An operator on the other end converted the dots and dashes into a regular message. Bell’s first telephone call went over the same wires used for telegraph messages. As the telephone became (34)……and more popular, it largely replaced the telegraph. Today, our huge telephone network does many things besides carrying telephone calls. It sends copies of letters and pictures from one machine to another, called a (35)…………machine…

Question 31: