COULD-COULDN'T-COULD...?
                                             
                                          
                                          
                                        
											 
											could, couldn't, could, could, couldn't, could, could, could, couldn't, couldn't, could
Answer:
A:
1. Could
2. Couldn't
B:
1. Could
C:
1: Could
2: Couldn't
D:
1: Could
2: Could
F:
1: Couldn't
2: Could
Explanation: ta-da! :]