Problem with enabling and playing audios

Hello,

the function below is supposed to simulate a "dialogue", where based on a pressed key it plays an audio clip (with playing an opening sentences at the beginning). However, when it gets to the lines after WaitForSeconds(2), I don't see the objects which were supposed to spawn and nothing happens after I press v,b,n or m. I have no idea about what might be causing the problem and I would appreciate any help. I am able to provide more details, of course.

And, btw, after that WaitForSeconds(2) line, when I pause the game, it seems like the objects are activated, but I don't see them. And, these game objects are all children of a bigger object, if that is to any help.

 function OnTriggerEnter () {
 
 audio.PlayOneShot(IHaveCustomer);
 
 yield WaitForSeconds(9);
 
 animation.Play();
 
 audio.PlayOneShot(HowCanHelp);
 
 yield WaitForSeconds (2);
 
 WhatIsThis.SetActive(true);
 WhoAreU.SetActive(true);
 HowCanIGetO.SetActive(true);
 
 if (Input.GetKeyDown(KeyCode.V)) {
 audio.PlayOneShot(WhatIsThisPlace);
 }
 
 if (Input.GetKeyDown(KeyCode.B)) {
 audio.PlayOneShot(WhoAreYou);
 }
 
 if (Input.GetKeyDown(KeyCode.N)) {
 audio.PlayOneShot(HowCanGetOut);
 
 yield WaitForSeconds(10);
 WhatIsThis.SetActive(false);
 WhoAreU.SetActive(false);
 HowCanIGetO.SetActive(false);
 
 WhereArePar.SetActive(true);
 
     if (Input.GetKeyDown(KeyCode.M)) {
 audio.PlayOneShot(WhereAreParts);
 
 yield WaitForSeconds (14);
 WhereArePar.SetActive(false);
 EndConversation.SetActive(true);
 
     if (Input.GetKeyDown(KeyCode.X));
     monster.SetActive(false);
     audio.PlayOneShot(Scary);
 
 }
     
 
 }
 
 }