1. I just called the travel agency. It’s all set.

Key Points: Set (“all set” meaning all prepared in spoken English)
(1). be set on sth./doing sth. (decide to do sth.)
She’s very set on going to the party.
(2). be ( dead ) set against sth./doing sth. (be against sth. strongly)
The manager was dead set against the plan.
(3). get set (to be prepared)
Get set. Go!
(4). have one’s heart set on sth. (make the decision to do sth.)
I’ve got my heart set on going to Paris this winter.

2. Have you run up against any problems in getting your passport renewed?

Key Points: get sth. done VS have sth. done
get sth.done VS have sth. done (The former “get sth. done” means sth. that is easier; the latter one means it is much easier)
1) I must gel my bike repaired.
(2) Where are you going to get your hair cut?
(3) Finally I got my pay raised. (can’t change with “have sth. done”

3. I don’t know how you can eat so much yet never put on any weight.

Key Points: Take
(1). take back
I take back what I’ve just said-you are really an honest man.
(2). take…under one’s wing
It is the duty of the elder brother to take the young brother under his wing.
(3). take…for granted
I took it for granted that you would come along, so I bought you a ticket.
(4). take advantage of:
It’s unethical to take advantage of an innocent girl.
(5). take a leaf out of someone’s book
Peter excels in academic work, but his younger brother doesn’t. I think he should take a leaf out of Peter’s book.