Hello brother Bin Thabit ,
Thanks alot for your explanations and you really did well . I think there is a mistake in this sentence which says " One of the most fame programs in the world is opera program. In this sentence ,however, you are describing the program . So , the sentence needs an adjective instead of a noun. It should be like this " One of the most famous programs in the world is Oprah Program . Just compare the two sentences you will see the difference ..

With my best regards to you all . "