— The floor is too dirty.
— I know. It _______ for weeks.
| A．hasn’t cleaned | B．didn’t clean |
| C．hasn’t been cleaned | D．wasn’t cleaned |
Alexander tried to get his work _______in the medical circles.
| A．to recognize | B．recognizing | C．recognize | D．recognized |
The looks on the children’s faces suggested that the question was really .
| A．Confused; confusing | B．Confused; confused |
| C．Confusing; confused | D．Confusing; confusing |
The doctor thought ____ would be good for you to have a holiday.
| A．this | B．that | C．one | D．it |
—Have you finished the book？
—No. I’ve read up to _____ the children discover the secret cave.
| A．which | B．what | C．that | D．where |
It never occurred to me _____ you could succeed in persuading him to change his mind.
| A．which | B．what | C．that | D．if |