1. broke means "to have no money"
Example: I have to borrow some money from my Dad. Right now, I'm broke.
2. Cut it out! means "stop doing something bad"
Example: That noise is really annoying. Cut it out!
3. drop someone a line means "send a letter or email to someone"
Example: It was good to meet you and I hope we can see each other again. Drop me a line when you have time.
4. figure something out means "come to understand a problem"
Example: I don't understand how to do this problem. Take a look at it. Maybe you can figure it out.
5. fill in for someone means "do their work while they are away"
Example: While I was away from the store, my brother filled in for me.