How do I preload multiple scenes?

I want to make it so that I can preload a specific list of scenes for each scene and unload them once the player is out of that scene (eg: scene 1 preloads 2,3,4 then the player enters scene 2 it loads 1,5,6 and unloads 3 and 4).

I would just like to preload a number of scenes without loading them but t$$anonymous$$s code loads them as soon as they finish loading. So far my code for my first scene looks like t$$anonymous$$s (preloads scene 2,9,8, unloads 3,5,6,4,10):

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 using UnityEngine.UI;
 
 public class SceneMan : MonoBehaviour
 {
 
 
         public void Start()
         {

             StartCoroutine(PreloadReady());
 
         }
 
     IEnumerator PreloadReady() {
 
             AsyncOperation TwoLoad = SceneManager.LoadSceneAsync("Room2");
             AsyncOperation NineLoad = SceneManager.LoadSceneAsync("Room9");
             AsyncOperation EightLoad = SceneManager.LoadSceneAsync("Room8");
 
             AsyncOperation ThreeUnload = SceneManager.UnloadSceneAsync("Room3");
             AsyncOperation FiveUnload = SceneManager.UnloadSceneAsync("Room5");
             AsyncOperation SixUnload = SceneManager.UnloadSceneAsync("Room6");
             AsyncOperation FourUnload = SceneManager.UnloadSceneAsync("Room4");
             AsyncOperation TenUnload = SceneManager.UnloadSceneAsync("Room10");
 
             TwoLoad.allowSceneActivation = false;
             NineLoad.allowSceneActivation = false;
             EightLoad.allowSceneActivation = false;
 
             
 
         w$$anonymous$$le(!TwoLoad.isDone)
             {
                 yield return null;
                 Debug.Log ("Loaded");
             } 
 
 
             w$$anonymous$$le(!NineLoad.isDone)
             {
                 yield return null;
                 Debug.Log ("Loaded");
             } 
 
             w$$anonymous$$le(!EightLoad.isDone)
             {
                 yield return null;
                 Debug.Log ("Loaded");
             } 
 
     }
 
 }