The opening scenes of the play tell us a lot about Richard's character. And that character—wicked, scheming and insanely ambitious—is expressed through Richard's numerous soliloquies. The House of York has achieved victory in its seemingly endless war with the rival House of Lancaster. Yorkists can smile again, enjoying themselves by dancing in their ladies' chambers to the seductive tones of the lute.
        
             
        
        
        
A. Serpentine is your answer
        
                    
             
        
        
        
Answer:
1 I talked to him on Monday. --> CAN'T CHANGE
2 I hated school when I was a teenager. --> I used to hate school when I was a teenager.
3 My parents didn't eat out very often. --> My parents didn't use to eat out very often.
4 We visited our grandmother every weekend. --> We used to visit our grandmother every weekend.
5 I went to the cinema with Mark yesterday. --> CAN'T CHANGE
6 Did you watch a lot of TV when you were a child? --> Did you use to watch a lot of TV when you were a child?
Explanation:
First, let's understand why we can't change numbers 1 and 5. "Used to" can be employed to refer to habitual actions in the past, that is, actions that happened frequently. In numbers 1 and 5, we are talking about a single action that happened at a specific time in the past, not about actions that happened often. Therefore, "used to" is not applicable to them.
All the other sentences are speaking of actions that happened often during a period of time in the past. If the sentence is affirmative, all we need to do is add "used to" before the main verb in its base form. If the sentence is negative, we use "didn't use to" before the main verb. Interrogative sentences place the auxiliary "did" before the subject, followed by "use to" and the main verb. Note that, in the negative and interrogative forms, it's "use", not "used".
 
        
             
        
        
        
Both A and C are correct. 
 
        
             
        
        
        
1.- Wow! That is a great idea. I'd love to join you, but I have a softball tournament that day.
2- Uncle Carl said, "we would like you to come to the reunion." but my mom told him that we would not be able to make it.
3- Because I had a dentist appointment at 1:30 pm, I had to leave school early.
4- The story, called out in the woods, is one of my favorites.