单项选择题


Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions.
Now listen to the passage.
According to tile talk, what did David Sarnoff predict about radios

A.They would get smaller in size.
B.Their signals would travel further.
C.They would become less popular than television.
D.They would be common household items.