This is my sister’s      , Lily. She is      to me.

 —____, Tom. Is this your pen?—No, it isn’t. I think it’s ____.

 Look! There are so many         eating grass on the hill. 　　

-Tom, do you know David Smith?-Sure. He is my best friend and our __________ has lasted for years.

Lingling is a　　　. She works in a hospital.