A. Let me see. I think it's a toilet for a pet（宠物）.

B. Yes. I do. I like studying them. 

C. Do you know anything about the public signs?

D. OK. What does that sign on the door mean?

{#blank#}1{#/blank#}—{#blank#}2{#/blank#}—{#blank#}3{#/blank#}—{#blank#}4{#/blank#}

A . Oh. Really? May I have a look?（真的吗？我能看看吗？）

B . It's nice. I like it.

C . I have a monkey.

D . Sure. Here you are.

{#blank#}1{#/blank#}She's my mother.

{#blank#}2{#/blank#}No, she isn't.

{#blank#}3{#/blank#}Guess!

{#blank#}4{#/blank#}Is she your sister?

{#blank#}5{#/blank#}Who's that woman?

{#blank#}1{#/blank#}Which grade are they in?

{#blank#}2{#/blank#}Are they new?

{#blank#}3{#/blank#}They are in Grade Four.

{#blank#}4{#/blank#}Who are they, Tom?

{#blank#}5{#/blank#}Yes, they are.

{#blank#}6{#/blank#}They are Bill and Jill.