Thank you for your corrections.
[STRIKE]that[/STRIKE] The book says "the radio" (no comma here) [STRIKE]and give[/STRIKE] must be used in the [STRIKE]sample[/STRIKE] example sentence below.
I listen to the radio a lot.
Aha! Now it makes sense. In that specific context, "the radio" is obligatory. When we are talking about the medium of communication used, we do use the definite article.
I listen to the radio every day.
He watches the television twice a week. (Note that it's also possible to use no article there.)
I read the newspaper to find out the financial news.
If you are simply talking about the piece of equipment, "radio", then all the articles are possible.
I have a red radio.
There is a radio in this room. Can you see the radio?
I have owned six radios.
There were ten televisions and lots of radios in the shop window.