6.I didn’t know your telephone number; otherwise I______.

A. would have called                                       B. would call

C. called                                                        D. should call

7. In the early morning my mother was in the kitchen ______breakfast for us.

A. prepared                                                    B. preparing

C. having prepared                                          D. to have prepared

8.1 would have told him the answer had it been possible, but I ______ so busy then.

A. had been                                                    B．have been

C. was                                                           D. would be

9. Our company will _____ all the costs of the repairs.

A. spend                                                        B．take

C. bear                                                          D. make

10. A few minutes after the plane had taken off, it developed engine trouble and______.

A. crashed                                                      B. dashed

C. stopped                                                      D. blushed