1. Listen! Someone _______ (sing) in the next room.
2. There _______ (be) an exhibition of art in the museum tomorrow.
3. Everyone in our class _______ (enjoy) music very much.
4. It's so cloudy. I think it _______ (rain).
5. We are looking forward to _______ (go) sightseeing.
6. When is the best time _______ (visit) your hometown?
7. The thief tried _______ (run) away but the policemen _______ (catch) them in the end.
8. Is it difficult _______ (finish) _______ (write) the article in one day?

A. to live
B. living in
C. to live in
D. live in

A. to live in   
B. to live     
C. living in       
D. live in 

A. ride      
B. to ride    
C. riding     
D. for riding

A. to have a meal            
B. to have a rest    
C.having a rest            
D. having a meal

A. to depend                        
B. to depend on            
C. to be depended                    
D. to be depended on

A. did            
B. do            
C. doing          
D. to do

A. to be big enough              
B. to big enough
C. to be enough big                  
D. enough big to be

A. Keep    
B. Keeping  
C. To keep    
D. Having kept

A. to wait in line  
B. to pick up the litter
C. to smoke          
D. to keep your voice down