Why is my code not working?

Why is this code not working. I have not used UnityAnswers before. I am using C#:-

 using UnityEngine;
 using System.Collections;
 
 public class SwapObjects : MonoBehaviour 
 {
     public GameObject Stone;
     public GameObject Cobble;
     public GameObject Dirt;
     public GameObject Grass;
 
     void Update () 
     {
         if(EventType.KeyDown(KeyCode.U))
         {
             Stone.SetActive(true);
             Cobble.SetActive(false);
             Dirt.SetActive(false);
             Grass.SetActive(false);
         }
         if(EventType.KeyDown(KeyCode.I))
         {
             Stone.SetActive(false);
             Cobble.SetActive(true);
             Dirt.SetActive(false);
             Grass.SetActive(false);
         }
         if(EventType.KeyDown(KeyCode.O))
         {
             Stone.SetActive(false);
             Cobble.SetActive(false);
             Dirt.SetActive(true);
             Grass.SetActive(false);
         }
         if(EventType.KeyDown(KeyCode.P))
         {
             Stone.SetActive(false);
             Cobble.SetActive(false);
             Dirt.SetActive(false);
             Grass.SetActive(true);
         }
     }
 }

The 4 errors I am getting is

Assets/SwapObjects.cs(13,30): error CS0119: Expression denotes a value, where a method group was expected

Assets/SwapObjects.cs(20,30): error CS0119: Expression denotes a value, where a method group was expected

Assets/SwapObjects.cs(27,30): error CS0119: Expression denotes a value, where a method group was expected

Assets/SwapObjects.cs(34,30): error CS0119: Expression denotes a value, where a method group was expected

All the same. What am I doing wrong?