Australia is nearly as large as the United States, but most of it is too dry for people to live in. Around this dry part are large sheep and cow farms. A few of them are as large as the smallest states in America. Often the nearest neighbours are several hundred kilometers away. The two-way radio is very important to people who live on these great Australian farms. It works much like a telephone. A person can listen to someone else talk and then give an answer. For example, people on the large farms could talk to a doctor far away. They could tell the doctor about someone who was ill, and the doctor could let them know how to look after the sick person. As the large farms were so far from towns, the children could not go to school. Radio schools were started for them in some places. At a certain time each day, boys and girls turn on their radios and listen to teachers in cities far away. Families on the large farms wanted to give news to their neighbours. The programme 'Round Robin Talks' by radio was started to keep families in touch with each other. They could talk about who was going away and who was ill. The men could talk about their sheep and cows and how much money the markets would pay for them. In many ways the radio became a newspaper for the farm people of Australia. In the passage 'the two-way radio' is ______.