How do you make text active and inactive using a script?

I am trying to make an interactive story book which has different text on different pages. I want it so that when you “turn the page” the text changes.
I have created a canvas and put the text from the pages at their positions as different text elements and have given them their colours.
What would the script look like to control which text element is active or not? As I can’t figure out which class these text objects come under because when I make a public GUIText variable it won’t let me drag the text in the variable box like I have done with my other game objects.

You are using UI.Text class in your canvas, I guess you need to add a namespace in your script:

using UnityEngine.UI;

and then declare a