已知直线l₁：ax﹣y﹣b=0； l₂：bx﹣y+a=0，（a≠b，ab≠0），则它们的图象为（　　）

Jan：I have new photos of my family, but they're not very good. This is my sister…
Mark：Where is she?  Is she at the library?
Jan：No, she's in the living room. She s doing her homework. And that s my brother.
Mark：Is he doing his homework, too? What's he eating?
Jan：He's watching a scary movie on TV and eating french fries.
This is a picture of my aunt and my mother.
Mark：Is that -your mother in the pool?
Jan：No, that's my aunt. My mother can't swim. And this is my mother and my aunt at the shop. They really like shopping and eating at the shop. Mark: Interesting photos.