阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填人一个适当的词或使用括号

中词语的正确形式填空。

     The two-way radio is very 1______ (use) to people who live on those great Australian farms. It 2______

(work) much like a telephone. A person can listen 3______ someone else talk and then give an answer. For

example, people on the large farms can talk to a doctor far 4______. They can tell the doctor about someone

who is ill, and the doctor can let them know how to 5______ after the sick person.