It was quite a serious accident, _________ caused by careless driving.
| A．which I think was | B．I think which was |
| C．which I think it was | D．I think which it was |
The girl was badly hungry. When she saw the food on the table, she looked around and___her hand for it.
| A．brought out | B．came out | C．reached out | D．gave out |
The parents waved and _____ the train until it was out of sight.
| A．saw | B．noticed | C．observed | D．watched |
Some researchers believe that there is no doubt ____ a cure for AIDS will be found.
| A．whether | B．what | C．which | D．that |
My sister has been feeling ______ since she started her first job. She can’t sleep well.
| A．stressed | B．unpleasant | C．confident | D．sudden |
Not only ______ a city and a republic, but ______also to become the capital of one of the largest empires in history.
| A．was Rome; was it | B．was Rome; it was | C．Rome was; was it | D．Rome was; it was |