When you do not know what to say



When you do not know what to say    
I’m at a loss for words.        
I’m speechless.        
I’m dumbstruck.        
No comment.        
I have no response.        
I have nothing to say.        
I have nothing to add.        
I don’t know what to say.
 What can I say?
What do you want me to say?
 You got me there.