You can imagine what great trouble they have________the problem________.

A．to solve；being talked about

B．solving；discussing

C．to solve；to talk about

D．solving；being discussed

You can’t imagine what great trouble they have _____ the problem _____.

A. to solve; being talked about               B. solving; discussing

C. to solve; to talk about                    D. solving; being discussed

You can’t imagine what great trouble they have _____ the problem _____.

A. to solve; being talked about      B. solving; discussing

C. to solve; to talk about           D. solving; being discussed

You can’t imagine what great trouble they have _________ the problem_______.

   A. to solve; being talked about     B. solving; discussing

   C. to solve; to talk about          D. solving; being discussed

You can’t imagine what great trouble they have _____ the problem _____.

A. to solve; being talked about      　　　 B. solving; discussing

C. to solve; to talk about   　　　　　    D. solving; being discussed

You can’t imagine what great trouble they have _________ the problem_______.

1. A.
   to solve; being talked about
2. B.
   solving; discussing
3. C.
   to solve; to talk about
4. D.
   solving; being discussed

You can’t imagine what great trouble they have _____ the problem _____.

A. to solve; being talked about             B. solving; discussing

C. to solve; to talk about                 D. solving; being discussed