Here are the answers to the there/it fill-in-the-gap exercise:
A: There is someone on the phone for you. I think it's Jim.
B: OK, thanks.
A: Look! It is your friend.
B: Oh yes! It's Jamal.
A: Have you got an umbrella?
B: No, I left it at home. Can I borrow yours?
A: How did you like Henry's speech?
B: It was too long and rather boring.