21. — Could you tell us the exact date of the accident?
—I’m afraid not. I just know it was ____ Sunday because everybody was at _____ church.
    A. /; /                    B. a; /                            C. /; the                         D. a; a
22. I had great difficulty _____ the suitable food on the menu in that restaurant.
    A. find                  B. found                        C. to find                       D. finding