A. It            
B. It's        
C. Its

例句：
—what's this?
—It's a pen.

1.
___________________
___________________

2.
___________________
___________________

3.
___________________
___________________

4. 
___________________
___________________

5.
___________________
___________________

1.Their dictionaries are on the desk.  (对画线部分提问)
_____ _____ their dictionaries?
2.There is a library behind the science lab.  (变成一般疑问句,并作肯定回答)
--- ______ _____ a library behind the science lab?  
--- Yes, _____ _____.
3.My book is behind the desk. (变成一般疑问句,并作否定回答)
-- _____ ______ book behind the desk?  
-- No, it _____.
4.They are not pencil- boxes.  (改为单数句)
It ____ _____ ____ pencil-box.
5.You and I are in the gym now. (用复数第一人称代替画线部分)
______ are in the park now.

A. I'm fine          
B. I'm 13 years old        
C. I'm from Liuzhou

A. Once
B. Two times a week.
C. For two hours
D. Once a week

A. What's the time  
B. Where is it      
C. How much is it    
D. Is it a clock

A. She is my mother  
B. She is a policeman  
C. She is a nurse

A.How is it going?
B.How is the weather?
C.How is it like?
D.Do you like the weather?

A. He's fine, thank you.
B. He's watching TV now.
C. He's tall and thin.
D. He's a famous doctor.

A. What does  
B. How is    
C. Where does      
D. How old is