They listen to the radio in the morning.
What do they listen to in the morning? - что
Where do they listen to the radio? - когда
Why do they listen to the radio in the morning? - почему
What do they listen to the radio in the morning for? зачем
They listen to the radio in the morning.
What do they listen to in the morning? - что
Where do they listen to the radio? - когда
Why do they listen to the radio in the morning? - почему
What do they listen to the radio in the morning for? зачем