_________ I admit that the problems are difficult, I don't agree that they cannot be solved．

1. A.
   In spite of
2. B.
   While
3. C.
   As
4. D.
   Despite

__________ I admit that the problems are difficult, I don’t agree that they cannot be solved.

A. When   B. While     C. As     D. Since

_____ I admit that the problems are difficult , I don’t agree that they cannot be solved.

A. While                   B. Suppose     C. Because                      D. as though

_________I admit that the problems are difficult, I don’t agree that they cannot be solved．

A．While             B．Since              C．Before              D．unless

__ I admit that the problems are difficult, I don’t agree that they cannot be solved.
A. Since    　　　 B. As      　　　　 C. Even though　　　    D. Because