Basically that means they will do everything they can. Think of the full range as the whole amount. An example would be, "I'm going to take a full range of measure to ensure I learn English."

A full range of >you can think of it as "many different types of something to make it a complete set " > We have a range of girls for you to choose from. > Yes , I can see that . But, where are the blonds ? This is not as full range as I expected . Full range >a complete set of something . >I want to see the full range of this new type of dress > Not just these 3 . I know the full range is 6 dresses