The one possible advantage of hearing the characters' voices as opposed
to silently reading the scene is that it helps listeners keep track of
which woman is speaking. Through audio recording as opposed to silently
reading a play, it can also help listeners interpret the characters'
emotions and motivations
In terms of the first question, "They" would be an objective pronoun, but it should be noted that this does not have to be so. for the second, the answer is "my".
Answer:
I expect you will be surprised to get a letter from me.
Explanation: