A、Military communication officers. B、People who treated radio technology as a hobby. C、People who lived in big cities. D、People

It was an Italian inventor who created the first wireless device for sending out radio signals in 1895. But not until the American inventor Lee De Forest built the first amplifying vacuum tube in 1906 did we get the first radio as we know it. And the first actual radio broadcast was made on Christmas Eve of 1906. That’s when someone working from an experimental station in Brand Rock, Massachusetts, arranged the program of two short musical selections, a poem and a brief holiday greeting. The broadcast was heard by wireless operators on ships with a radio through several hundred miles. The following year, De Forest began regular radio broadcasts in New York. These programs were similar to much of what we hear on the radio today in that De Forest played only music. But because there were still no home radio receivers, De Forest’s audience consisted of only wireless operators on ships in New York harbor. There is no doubt that radio broadcasting was quite a novelty in those days. But it took a while to catch on commercially. Why? For the "simple fact that only a few people, in fact, only those who tinkered with wireless telegraphs as a hobby, owned receivers. It wasn’t until the 1920’s that someone envisioned mass appeal for radio. This was radio pioneer, David Sarnoff, who predicted that one day there would be a radio receiver in every home.
Questions 22 and 25 are based on the passage you have just heard.
22. When was the first actual radio broadcast made?
23. Where did De Forest begin regular radio broadcasts?
24. Who had receivers in the early days of radio?
25. What did David Sarnoff predict about radios?