There ____ a terrible accident then, ____ three passengers were killed and twenty were injured as well.
| A．was occurred; which | B．was occurred; in which |
| C．occurred; which | D．occurred; in which |
The visiting Minister expressed his satisfaction with his talk,__________ that he had enjoyed his stay here.
| A．having added | B．to add | C．adding | D．added |
I just don't understand_______ that prevents so many Americans from being as happy as one might expect.
| A．why it does | B．what it does | C．what it is | D．why it is |
The fire started in the basement and quickly____________ to the first floor where it destroyed all the______________ in the language lab.
| A．was spreaded;furniture and equipments | B．was spreaded ;furniture and equipment |
| C．spread;furnitures and equipments | D．spread ;furniture and equipment |
Mary ___________to see you．She．_________ for you downstairs at the moment．
| A．has come；is waiting | B．came；is waiting |
| C．has come；waited | D．came；was waiting |
The bad weather meant__________ the rocket launch(发射)for 48 hours,．
| A．delaying | B．having delayed |
| C．to delay | D．to have delayed |